To all of you that encounter performance problems and have sites with lots of categories and products.
Whenever I (rarely) send Jon a ticket, I always get a reasonably timely answer. But that's not the reason for my post though. The reason is the following - I also had an issue where a site of mine (with lots of categories) took lots and lots of CPU, and since the CPU report mentioned cdseo, I thought cdseopro was the culprit.
As it turned out, what Jon said is absolutely correct - cdseopro.php is showing as the URI component because it runs the majority of the x-cart pages , not necessarily because it is the culprit.
The guilty party in my case (and I believe in most of yours as well) is a section of code in the include/categories.php file. If you implement the code fix, I believe you will suddenly see a big difference. The code fix can be found in the first post of the thread
http://forum.x-cart.com/showthread.php?t=40093 under "Tracking down the bottleneck".
Good luck!