I have installed DataAssist to a windows XP machine and the exact same thing is occuring. I have tried this on teh WinXP machine with both Dreamweaver CS4 and CS3 as well as different version of DataAssist.
One thing that might be worth mentioning is on the first page where you select your connection and table, the table has about 15 temp table entries usually looking similar to:
~TMPCLP124151
I have examined the database and I cannot see anything other than the necessary tables and certainly no temporary tables.
Kelly