well, even though my memory passed memtest repeatly a week ago, i just started it again (more or less pulling my hair out at this stage), and what do you know, i get an error this time.
so, i have new memory on the way, should be here early next week, i'll post back then. (yes, that means that the 1st set of ram i was using failed memtest, and now the 2nd set, which i've been using about 10 days, also now fails memtest, hopefully 3rd times a charm!)
thanks again for your patience and help in my thread, i greatly appreciate it!