WWForum access slowing down

Hi,

I am using a WWForum 7.01 with access database, I have nearly reached 90 000 posts and the database is nearly 100Mb.

The forum is now very slow and freezes at least 3 times a day (have to reboot server). I'd say it does that when there are around 40/50 people posting.
Is that normal? I've heard that access databases were becoming unstable around that size.

I thinking of shifting to a 7.9 MSQL version, hoping it will be better.

Any advice for the migration would be welcome . Are there any tools to automate the conversion, etc.

Thanks in advance.

my forum is there : http://www.munsterfans.com/forum//default.asp