Java Security

Hi friends,

I have a very serious problem to encrypt and decrypt data with AES algorithm. My problem is the following:

I found several examples to encrypt and decrypt data with AES. Well, in that point, I proved that examples with a only program, and the encryption run perfectly. Then, I passed the examples code to my aplication, in which I have a java client and a java server. My idea is encrypt the comunication between two parts, to set the channel more sure.

When I encrypt the data in the java client, the encryption is well, but when I want to decrypt that data (I send the data on Internet with socket), sometimes the decryption is well, and other time the server shows me the following message:

javax.crypto.IllegalBlockSizeException: Input length must be multiple of 16 when
decrypting with padded cipher
at com.sun.crypto.provider.SunJCE_f.b(DashoA13*..)
at com.sun.crypto.provider.AESCipher.engineDoFinal(DashoA13*..)
at javax.crypto.Cipher.doFinal(DashoA13*..)
at AES.desencriptarDatos(AES.java:131)
at AplicacionServidor.main(AplicacionServidor.java:84)

Anyone can help me please? I want to finish this part and I have taken a lot of time with the theme. With other examples that I found on Internet I obtain the same result. Anyone knows the answer to this situation?

Thanks.