Yep there is not a problem with php 4.3.6 and mysql_num_rows. I have installed 4.3.6 and also went back and checked phpinfo pages on some of the last installs I have done and many are running 4.3.6 and some even 4.3.7 with no problems
Has to be an isolated incident where RBL's host messed something up when they updated their php/mysql
rbl you can PM me a test account and url etc and I will take a look
