Check out this thread.
If you click on the memory card you can delete the Contacts (should be bloated 60mb+) I did this two weeks ago and haven't had a problem since.
You might want to try one of the cache clearing tools in the market. You have to be root though. The cache clearing tools did not work for me, but they do work for some people. I was finally successful deleting the cache from the browser settings, but apparently that is not working for you.
Worst case, you may have to factory reset.