Yes os 9 is not very stable, and limewire for os 9 I guess is not well-written either yet.

To they guy with macs at school -- you can only allocate as much memory as you have ram available. Flash 5 takes a lot of ram to work well. It may help to set a correct amount of virutal memory to support the amount you allocate to applications. On os 9, virtual memory can safely be set to a maximum of 1/2 total ram + total ram -- you should write in this sum in the virutal memory box.

If your school gets a ram upgrade (the computers really should have 512 ram or more, as ram is cheap), they should install os X. Most, if not all of that software runs within os X under its os 9 "classic" mode (basically os 9 boots up from within os X). This does require a greater amount of ram (as does os X itself), however I have had few memory issues with running classic mode with Fireworks, a web browser, Dreamweaver, and Flash running simultaneously with 512 meg of ram.