brokenwindow,
I too had problems with my Core2 in the beggining. But I managed to take care of it (thanks to tech-support and updated driver). I'm afraid that all the bad reviews are true, but Lexicon is doing a good job in solving most of the problem. What you need to do is to download the latest up-dated version of the Core2 driver. Follow the direction the way it is written out i.e., cold boot instead of re-boot (trust me on this one, they know what they're doing). Delete all your original driver along with whatever program came with it before you install the latest driver. If you follow the instruction very well you should have your Core2 working.
Note: Lexicon claims that Core2 will not work with Athalon for some unknown reason. But I recentlly spoke with a techie there and he said that he had at least 3 people who had theirs working using Athalon 800 with VIA 133 chipset motherboard. I suggest just go with Pentium (safer and will save you the hassle in the long run).
Like what I said, follow the instruction to a tee and you will be happy. As a matter of fact, I am running my Core2 with a miniscule system of P-III 550 with 256 sdram and a couple of 9 gig scsi uw. I get 24 trks with effects easy with cpu usage of approx. 10-20% using Cakewalk 9.
Well, hope you the best luck.