This past weekend I tried to upgrade a site from 2.0.5 to 2.0.7. This failed miserably.

Firstly, no sooner did I get more than 1 user logged into the database I started getting errors:

internal gds software consistency check (Attempt to call GlobalRWLock::unlock() while not holding a valid lock for logical owner)

Secondly, it was at least an order of magnitude slower that 2.0.5, even with just a single user logged in.

I finally had to revert them to 2.0.5. The minute I put the old version in place the lock errors went away and the speed went back to normal.

What the heck?????

And before your suggest it, my first inclination was to upgrade them to 2.5 but that also failed because of some problem with my UDF. See my prior post about ib_util_malloc errors. Still haven't figured that one out.