http://bugs.winehq.org/show_bug.cgi?id=23323
--- Comment #46 from Devin Cofer ranguvar@archlinux.us 2010-06-23 21:06:45 --- All you need is time :) It's just testing between each individual patch between those two Wine versions to find the exact patch that broke.
There's a fantastic walkthrough here, if you can help: http://wiki.winehq.org/RegressionTesting