No, I'm afraid there is nothing usefull in /tmp
"find /tmp -atime 1" only shows crap.
Is it possible to insert the dump from ispconfigdb taken before the update and then redo the update?
This all things sound like this is the perfekt time to update to deb 4.0 ("never change a RUNNING system"). Would it be possible to reinstall ispconfig on etch and insert the dump as a backup?
Thanks for your effort.