External memory full error on phone

I am having LG Viewty for my phone i purchased a Micro SD card 4 GB to put in and it seems that the telephone saturates. When in fact I want to take a picture, I have a message that says "External Memory full" and but my memory card having enough space. Can someone help me please?

Thanks

Did you know that the motives that accept SD cards (etc) always have a size limit accepted?

well now you know and guess what is the maximum size to yours?
The limit is 2GB

LG Viewty memory : 90 MB of internal memory and up to 2 Gbytes of additional memory How it will accept 4 GB memory card insert 2 GB memory card in your phone then it will work properly.