SMS Data Restore On 4.2.1 Crashes Messages App iPhone 3G

I took my old 3GS back to apple as the battery was starting to drain quickly. Ive been given a replacement 3GS & it has 4.2.1 on it & have tried restoring my SMS data back to the new phone, but when I open messages it crashes & exits. I reopen messages & the data is blank. I did restore my data from my backup from my previous 3GS. Im not sure if its a 4.2.1 problem or because of a new 3GS using the old 3GSs data. Hopefully someone has come across this problem with a solution to it as I have messages I would really like to keep.
iPhone 3GS iOS 4