i am interested to say the answer to this one myself. becasue i set up a
computer for a family member using ubuntu 10.4 and everything works great except
for the issue you are having.
I checked the package manager and searched for those packages and it said they
were installed. i tried updating still no help. i even downloaded the latest
version of java and installed from terminal but still couldnt get it to work.
any help here will be greatly appericated.

I have not tried Limewire, but I do have Frostwire installed and it works
fine. I have the proprietary java installed. You cna get Frostwire from
Getdeb.net. Flash non-free is in the repositories.