MySQL 5.0.23 'hangs' due to Coppermine

[Xandrios]

Hello,

I have a Coppermine 1.4.3 (stable) install with 70,000 pics and recently upgraded to MySQL 5.0.23. This is where the trouble started. Every once in a while, randomely, mysql hangs while executing a coppermine query. Sometimes it is 1-2 times a week, but it has happened 1-2 times an hour as well.

At that time all subsequent queries get queued because the tables are locked. A 'show processlist;' shows that there always is one coppermine query in 'sending data' state when this happens. Example:
"Sending data | SELECT COUNT(*) from cpg_pictures WHERE approved = 'YES' AND aid IN (1,2,3,5,6,7,8,9,10,11,12,13 | "
or:
"Sending data | SELECT `user_id`, `user_name`, `user_group`, `user_profile1` , `user_group_list` FROM `cpg_user |"

I have found that increasing the MySQL worker threads 'kinda' solves the problem. Not quite, because now MySQL uses 100% CPU on one core. But at least it (seems) not to hang anymore.
Are there any known issues with Coppermine and Mysql 5? I might be running an somewhat outdated version, however it is of the latest branch (1.4.x).

Any advice would be greatly appreciated!