No, I doubt that being a cafe member will stop the messages. In fact, I am a cafe member myself and still get the hella annoying "Server Too Busy" messages all too often. =)

I help run a datacenter, so if the administrators of the site would be willing to PM me privately, I might be able to help. It looks to be a MySQL machine load issue so the server load is simply too high at times and the database times out. We see this problem with vBulletin a lot on some forums we operate here.