by Ken Task.
So what 'other changes' did you make that might have bearing on the errors you were seeing? Share Back! ;)
Could still use file based sesssions on a temporary basis to get a look at those session files and how large they might be by adding the following line to your config.php
$CFG->dbsessions=0;
That takes affect immediately. One could then check out the moodledata/sessions folder and view the size/contents of session files.
To turn that back on ... just re-edit and comment out that line by adding
// in front. Again, that takes affect immediately.
'spirit of sharing', Ken