i am REALLY into folding and have tried most every client on most every OS. just as background info. i could never get the OS X SMP client to run under 10.4.X and i tried every client/config on almost every Mac intel system. really. loaded 10.5 and the current beta client, and it all just 'magically works'. mini, good. imac, good. mac pro, good/Great! so, the only point to the post is, if you tried the X SMP client before and couldn't get it to work, and have upgraded to 10.5... TRY IT AGAIN! it just works.