I just got Mathematica 3.0 for Power Macintosh. My old version 2.2.2 does not have this problem. When I try to calculate for example PI to 116,000 decimal places, the Kernal memory bar does not move, but at the end of the calculation it moves up off of the scale and the Kernal runs out of memory. I have 20 Megs allocated to the Kernal. In version 2.2.2, during the calculation, the memory bar moves up in small bursts and then moves back down again. It is as if the total amount of memory that is used in small bits at a time, and then recovered in Version 2.2.2, is used all at once in one big swoop at the end in Version 3.0! I calculated Pi to over 700,000 in Version 2.2.2, now 3.0 won't do 116,000? I did the Pi calculation just to compare relative speeds of the two versions, and it seems maybe I found a major flaw. I anyone can duplicate this on a Mac, let me know through E-Mail of by posting here. Thanks. I will notify Mathematica tech support of this also.