Just a point I thought of today after seeing someone else with the problem and this person being told to redownload, I am not using Verizon's 4.1, when I tried using it (I had 4.1 from Sprint in my BB) it told me I would be doing a downgrade, so I stayed with the Sprint all along. That may be the reason I am not getting the blank screen the rest of you are. So if after redownloading and reinstalling you still have the issue I would suggest upgrading to the Sprint version.
BB Tour 9650
Running OS 126.96.36.1994