[Deceptor]

venuusisthebest,

The kill cache hooks were only introduced in the latest version, which is why it only occurs now

logic,

I took a look at your site, I believe one of many of your modifications is stopping vB Optimise debug messages, or other operations. I can see that file cache reduces one query on your forum, but Memcache is not doing anything. The problem there is something with your Memcache, do you have the correct settings filled in for your /includes/config.php?

To sum up though, vB Optimise isn't working right due to confliction, and since you have a -lot- of modifications installed it's very hard to tell where the problem occurs, you'd probably need to turn a product off one at a time, and keep checking your forums debug info each time (you need to look at the drop down menu, very bottom of the debug info). Once you start to see 'vB Optimise' messages in the drop down menu, we can start getting a clearer picture of what is going wrong. If turning off a product doesn't work, turn it back on and move to the next to continue.

Also, I have to ask if your vBulletin forum files have been modified? If so those too could be the root of the issue.