Groupwise 5.5 – Need Service Pack?

I am running groupwise 5.5 clients using novell network software on a windows 98 SE system. I get frequent lockups when printing and just reading emails.

I am attempting to install the service packs on Novell’s web site. My questions:

Are there any other measures I can take, aside from upgrading to a higher version of Groupwise, to increase the stablility of the program?

When installing the service packs, is it like NT and all of them must be installed? Or can I just install service pack 5 and all of the previous fixes will be included.

Please advise