Java bonked? Get the 10.6 patch here
The Software update version is bonked, the latest bug fix is here
https://support.apple.com/kb/DL1573
Pasting: java -version into Terminal (Applications -> Utilities -> Terminal is the program that lets you access it) and pressing Enter should reveal this after the update which fixes the bug.
java version "1.6.0_51"
Java(TM) SE Runtime Environment (build 1.6.0_51-b11-457-10M4509)
Java HotSpot(TM) 64-Bit Server VM (build 20.51-b01-457, mixed mode)
Note: this version of Java is the newest that 10.6 will run, and unfortunately is not the as secure as Java 7, released only for Mac OS X 10.7.3 or later. Read this tip on updating to Mac OS X 10.7 or later before going down that path.
Note: PowerPC users entering this forum, should read this tip for 10.5.8 and Java. That includes all Macs that say G4 867 Mhz and higher (1 Ghz and higher), and G5 in Apple menu -> About This Mac
https://discussions.apple.com/docs/DOC-6491
Note: Intel users wanting to upgrade to 10.6.8 to get the Java patch, should read this tip:
https://discussions.apple.com/docs/DOC-2455
If you have the correct version of Java installed under 10.6.8, and it still has speed issues, the following tip was found by one of the other posters:
Go to Applications -> Utilities -> Java Preferences:
Go to the Network tab, and unflag "Keep temporary files for fast access"
This should work as long as you don't have any space constraints. The general rule about space is that the hard drive can't be more than 85% full.
Also do not use backup software simultaneously with other tasks, and make sure your Spotlight is properly indexed (Item #4 on: https://discussions.apple.com/docs/DOC-6921 )