That is a lovely plethora of ideas, thank you! I am very happy to report that I have made definite progress.
First, I downloaded and installed the WinUtilities program, ran most of the cleanups except for the RegKey and disk defrags. I was particularly interested in the Mem Optimizer, so tweaked the settings to create maximum free RAM.
Second, I went to the nVidia control panel, and changed all settings to concentrate specifically on performance. Would be happy to type out the specs, but don't want to bore everyone to pieces. The notables are:
Threaded Optimization=Auto
Texture Filtering-Anisotropic Sample Optimization=ON
Maximum Pre-rendered Frames=1
Antialiasing Transparency=multisampling
PhysX=disabled
In game options are set to high, with major changes as shadows off, grass @ 3/4, Vsync On, AA off, and sound quality at low (all of these options were present when the game crashed every hour as well)
Basic PC specs are i7 920 quad(2.67GHz), 6 GB 1066 DDR3, GTX 260, integrated HD audio (again, don't want to overinflate the post with an entire dxdiag-lol)
I agree Schot that this must be a resource issue. One, or both, of the aforementioned techniques have improved the game stability dramatically, allowing me two 4 hour sessions with liberal use of the map and cave hopping (most freezes occurred with these).
I am intrigued by the 4GB patch and the Sacred Cleaning Utility...I will try and hope to report more positive results. Thanks for all your input!
Cheers,
Buzz