I got a copy of Scannerz a few weeks ago to troubleshoot a problem that I had with a BRAND NEW Western Digital 2TB external drive. This Western Digital unit is about the cheapest built piece of crap I've ever seen in my life. The only good thing about it is the 2TB size. Aside from that, the cable is flimsy and the case is even worse. I was getting erratic I/O errors and Scannerz pointed me at the cable (which looks, like the case, like it was built by elves.) I replaced the cable with a good cable and the problems disappeared. I probably should have returned it but that takes time and the drive inside this POS case is supposed to be good, so I decided to keep it figuring if the case malfunctions I'll extract the drive and put it in something else. In any case, once that problem was fixed, I decided, for kicks, just to run "Performance Probe" which comes with the Scannerz package for free. As an FYI this system is a mid 2009 MacBook w/4GB of memory. Most of the time, and I'd like to stress the word "most" the system runs OK. In any case, one day I noticed tons of spinning beach balls along with very, very slow response to everything. I look at Performance Probe and notice that the CPU and Memory readings seem to be having a war with each other, meaning it's almost looks like they're trying to outdo each other for which can hog the most resources, and yet I'm running only Mail and I went to Weather.com to get the forecast using Safari (YOU'VE GOT TO BE KIDDING ME!! This now qualifies as bottlenecking????). I look at Performance Probe and it indicates the OS and all running apps are taking up 2GB of memory. I figure Spotlight is running, so I bring up Activity Monitor and it's clear that Spotlight isn't running (mds and mdworker threads aren't hyperactive) At this point I say "screw it, I'll check it out in an hour" because I didn't have time. I come back about 90 minutes later and Performance Probe is now telling me that 75% of the memory is in use. In use for what? I figure it's a bug in the program so I open up Activity Monitor and it tells me the exact same thing. The two report memory differently. Performance Probe sums all active and wired memory into one group on a pie chart (red) whereas Activity Monitor breaks out the two. You can see a picture of Performance Probe here: http://www.scsc-online.com/Perf Probe.html 75% of the fricking memory for what????? I haven't even been using the system! How did it manage to go from about 50% of the used memory to 75% of the memory WHEN I WASN'T DOING ANYTHING???? I should add that I have Snow Leopard on an external FireWire drive so I can use some old, now "not allowed" programs. I've done similar tests on it, and it isn't consuming any where the memory that Mountain Lion uses, and I'm not having any of the erratic, "guess what I think I'll lock up and hog all your memory for no apparent reason" bug (I assume they're bugs.) Are bugs like this well known? I've wasted (EMPHASIS: WASTED) time troubleshooting the system. I've run Scannerz on all HDs now, no problems. I've run AHT on it several times figuring I'll find some system error. No problems. I run it with Snow Leopard. No problems. I run Mountain Lion, and about 10% of the time I'm getting similar errors. I wish I could say, "Yes, I'm running MacKeeper because God Almighty has bestowed this wonderful product on us to save all of us from non-existent threats for about 50 bucks" but I know better than that. This looks like a bonafide bug. This is release 10.8.5. There's no excuse for this. and they want me to give me more money for Mavericks? Does Apple know what they're doing anymore???