I just installed LW 2.5 on my Mac (OS 9.1/Imac/64 mg RAM) It said installation was successful, but with errors. In the installation log I found:

Custom Action: com.limegroup.install.SettingsTranslator
Status: ERROR
Additional Notes: ERROR - class com.limegroup.install.SettingsTranslator.install() Unexpected Fatal Error:

All appears installed but when I try to open Limewire it says:
Invocation Target Exception and closes the application.
What do I need to do to make this work? It's driving me crazy. This is the third time I've downloaded Limewire and each time I get the same deal.

It's nearly impossible to run LimeWire on OS 9 w/ 64 MB of RAM. You could try setting virtual memory to 128 MB but the real solution here is to buy more physical RAM.