Golang, encrypting a string with AES and Base64

I’m trying to encrypt some text inside a database to be loaded and decrypted during program startup.

I have tried a few methods, including a third party library https://github.com/richard-lyman/lithcrypt to no avail. Using the following method encrypts/decrypts 8/10 items, but it seems that some padding residue is left behind at some point in the encrypt/decrypt. As it stands my code is like this:

package client                                                                                                                                                                                              
import (                                                                                                                                                                                                    
    "encoding/base64"                                                                                                                                                                                       
    "crypto/aes"                                                                                                                                                                                            
    "crypto/cipher"                                                                                                                                                                                         
    "fmt"                                                                                                                                                                                                   
) 

var iv = []byte{34, 35, 35, 57, 68, 4, 35, 36, 7, 8, 35, 23, 35, 86, 35, 23}

func encodeBase64(b []byte) string {                                                                                                                                                                        
    return base64.StdEncoding.EncodeToString(b)                                                                                                                                                             
}                                                                                                                                                                                                           

func decodeBase64(s string) []byte {                                                                                                                                                                        
    data, err := base64.StdEncoding.DecodeString(s)                                                                                                                                                         
    if err != nil { panic(err) }                                                                                                                                                                            
    return data                                                                                                                                                                                             
}                                                                                                                                                                                                           

func Encrypt(key, text string) string {                                                                                                                                                                     
    block, err := aes.NewCipher([]byte(key))                                                                                                                                                                
    if err != nil { panic(err) }                                                                                                                                                                            
    plaintext := []byte(text)                                                                                                                                                                               
    cfb := cipher.NewCFBEncrypter(block, iv)                                                                                                                                                                
    ciphertext := make([]byte, len(plaintext))                                                                                                                                                              
    cfb.XORKeyStream(ciphertext, plaintext)                                                                                                                                                                 
    return encodeBase64(ciphertext)                                                                                                                                                                         
}                                                                                                                                                                                                           

func Decrypt(key, text string) string {                                                                                                                                                                     
    block, err := aes.NewCipher([]byte(key))                                                                                                                                                                
    if err != nil { panic(err) }                                                                                                                                                                            
    ciphertext := decodeBase64(text)                                                                                                                                                                        
    cfb := cipher.NewCFBEncrypter(block, iv)                                                                                                                                                                
    plaintext := make([]byte, len(ciphertext))                                                                                                                                                              
    cfb.XORKeyStream(plaintext, ciphertext)                                                                                                                                                                 
}                          

It was mentioned to me that I might need to pad the string, but it seems strange that I would have to pad a stream cipher.

Below is an example of this error: http://play.golang.org/p/4FQBAeHgRs