I upgraded to InnoDatabase and in lib-comment.php, i changed "LOCK TABLE XXX" to "START TRANSACTION" and "UNLOCK TABLE XXX" to "COMMIT" on line 837, 863, 968, and 987. Anywhere else these needed to be changed?
When i test the post comment my page goes blank. Any suggestion?

Blank page

nevermind. it was a stupid mistake. I forgot to rename back comment.php file