Wow are you really still using Access 2.0??!! The only problems I have run into are with code and tab forms. Sometimes you have code issues because of the updates to the code library, but unless you have a lot of code I would not worry about that too much as Microsoft was pretty good about making it backward compatible. If you have forms with tab forms in them then you will most likley have to rebuild the forms using the new tab form functionality added with Access 97. There are probably other issues out there but I have not seen them. Have you tried making a backup copy and upgrading to see what happens?
GumbyD