Cant access webmail and firefox

Two questions, hopefully they will be quickies

1. I have a customer who has two macs and is on plusnet internet. For some reason we cant access his webmail on the G4 mac laptop but its fine in the more recent macbook. Im not too sure what the error is but i think its just a generic 'this page isnt working' type of thing. it happens with any browser. Is there some temp directory or cache i can clean to fix this?

2. Was there a fix for the problem with firefox 3.0.5 not working on the mac? Again, this is being experienced on the older laptop. Theres a bit info to be found on a google search but not much. Could thisbe whats messing up the above?

Thanks!!

 

Anyone? I actually thought these would be simple questions especially the browser cleanup one.