I downloaded OS 4.5 to my blackberry pearl. Ever since i downloaded this operating system my pearl keeps resetting itself. Does anyone know how to fix this problem. When i downloaded the application to my wife's pearl her's works great.

I would try a wipe and reload: How do I wipe the BlackBerry using Jl Cmder? - BlackBerryFAQ

I have done a memory wipe (which kept the new os system and did not convert back to the old). I have removed my battery and SIM card for a couple of hours and still no prevail.

There are a few things that have been pointed at as a culprit for this. If you do a search you'll find a few. The one that sticks out is a Media Card not formatted to the new OS.

I did not try the media card. I didn't even figure that would cause my device to act this way. But I removed my media card and I am no longer having this issue. Thanks for the advice.

Do a search for BBThumbs.dat for info on how to fix the card.