Thanks for the info. I checked your link and it looks like others have had similar problems. I've tried a few of these proposed solutions, and since there is no single solution that seems to make a difference for me, I will have to assume there is a bug(s) associated with some as yet unknown compatibility issue. I sent a request to Rockstar technical support several days ago and have only received automated responses from them.
I enjoyed MP2 and thought it was a great game, and I have owned several past Rockstar games that provided great gaming experiences. None of them have evoked as much frustration for me as MP3. For all it's stunning audio/graphical curb appeal, there are some glaring shortcomings with the game's operability and mechanics. And I agree with some other commenters here about the gaping holes in a story-driven shooter- if only because I believe there was a missed opportunity for creating a game that was an evolutionary step ahead of the previous installment in the series, simply by providing the player with a more compelling rationale to complete each sequence.
Think about it for a minute, if you take away the immersive elements of the story, you have 6-12 hours in a formulaic shooting arcade. To name just one of dozens of contrived sequences that left me wondering, when I got to the end of the dock scene and Raul coasts up in his speedboat to pull Max from the flaming wreckage, I couldn't help but ask, what was this guy doing all the time I am slogging through this thug-infested warren? Sipping a margarita? That kind of loose plot structure you expect from Mario Brothers, but feels incongruous in a game with serious pretensions of it's characters, and graphic gunplay. Okay, maybe its better to just turn off your brain and shoot.