EASYEDE  Luther and Chris - you should check to see if there is some other issue that is causing the problem. I use the program on an older MacBook G4, a MacPro Dual Core and a current iMac - all running on the latest version of OS X - and have no problems of any kind.  
(Version 4.4.6)

EASYEDE  Spargett, DragThing is much more than the Dock. I've been using DragThing for at least 5 years and it just gets better with each new version. My DragThing "Dock" has 8 tabs with each tab holding items relevant to a specific catagory such as "Applications", "Net", "Work", "Photography", "Games", etc. These tabs hold close to 100 items so unless you have a 4 foot monitor you'd be hard pressed to show all these item in the Apple Dock.

Check out the documentation on DragThing and you'll quickly see that it has MANY more useful features that the Apple dock doesn't have. I use the Apple Dock for those items I use VERY frequently and for quick access to minimized windows but DragThing is my Application/Folder/File command center.   
(Version 5.9)

EASYEDE  The negative comments regarding version 2.0 are correct - I was almost to the point of finding another spam filter myself. Then version 2.2 came along and it is back to being a robust effective spam filter. You owe to yourself to try 2.2 if you were previously turned off by the bugs in 2.0.  
(Version 2.2.2)