The current PPC version causes problems on my Mac Pro. If it is running (which it is all the time), it causes other Rosetta Applications to be unstable and unexpectedly quit. The only solution is to reboot. I have proven this by exhaustive testing and have sent an E-Mail to the author suggesting a UB version soonest. No reply to date. I swapped to Spamsieve a week ago running the 30 day demo and I haven't had one quit since that time. To let you know this is not a spur of the moment assertion - I have spent 10's of hours tracking it down. Hopefully the author will come out with a UB version soon.