sounds like a memory leak. bring up the system resource meter sometime and watch it over that 3.5 hour period and see what you notice. updating your java might help. what version are you using?

It's hard to say where the problem lies. You probably run out of memory for some reason. JavaFIBS does use more and more memory when time passes since each line of text in any text field add up to the used memory for example.  There also may be some memory leaks somewhere, and it has been a known problem in older java versions, but I don't know if it has been fixed.  It can of course be some stupid programming in JavaFIBS also that eats your memory.

I suggest that you download and install the latest versions of both JavaFIBS (1.007) and Java (1.4.2) itself and see if the problem persists. Do NOT download and install any beta versions of Java.

You can also try to clear the text fields every now and then if you get lots of text there (right button in the text field brings up a menu).

When I use to run out of memory on my win 98 puter for no apparent reason I shut down most programs to free any resources and then reload the programs again.  So when you notice that JavaFIBS starts to run too slowly, just shut it down and reload it again instead of waiting for it to completely freeze. If it still crawls after the reload, it may be some other program that eats your memory instead.

i dont know if this is related but this is the problem i had with javafibs.  i didnt notive that the javafibs played any slower over time because i usually only played one or two matches, however all of my other programs seemed to freeze up after i downloaded javafibs and or the java platform need to run JF.  the first time i didnt know what was going on and even rebooting didnt seem to help.  i then restored my computer to an earlier time (without JF) and everything was back to normal.  after about a week i again downloaded JF and the java program with the same results, which the only conclusion i could draw was that it was somehow affecting my computer.  ive since gone back to 3dfibs which ive never had any problems with and have found to be very user friendly