abbayarra: It sounds like something was corrupted upon installation. The game should not crash regularly at the same point. I've had this game for many years and its crashed on me many time. It almost always crashes after playing for quite some time. But then again, I tried something different today and the game crashed unexpectedly. The crashes most often seen are falling through the floor and textures incorrectly loading, then the game will crash soon afterwards. I'd reload and the game would be again good for several hours. I've borked my installation several times with mods and trying different things.
If you use something like galaxy it might have a feature to repair installation.

If all else fails, back up your save, do not delete it. Uninstall the game. Delete the entire folder with oblivion, run something like ccleaner. Make sure you clean up the registry entries.

Finally install the game again along with the one mesh using the correct mod installation program. The save should still be good. I've never seen a corrupted save game.

Greywolf1: I agree that it sounds like a corrupted installation (possibly caused by the texture pack - only a guess). But before going through the process described above, you might as well try to simply repeat the installation and then try again. Chances are that the registry entries are not damaged, and then this simple method is likely to work. If not, then it's really advisable to uninstall Oblivion, to make sure that everything is gone, including (and mainly) all registry entries associated with Oblivion, and to install the game again.