New threads post very slow. All else is fast...ideas?

[Codeman05]

Hey guys,

I could use a hand with my forum. I've noticed that over the last 2 weeks, it takes approximately 10-15 seconds for a "New Thread" to be submitted.

However, new replies, quick replies, etc... all take 1-2 seconds max (usually well under 1s).

Here is the list of products installed:
vBulletin 3.6.4
EWT - Thread Description
IRC Manager
Multiple Login Detector
Separate Sticky and Normal Threads
Supermod Permissions
Top 'X' Stats
vB Spell
vBadvanced CMPS
vBIspy WOL
Vbulletin Template Compressor
vBXirc 3.0.0 Beta 1
Welcome Headers

I have had all of those running for some time now, so I don't believe it is a product/plugin causing the problem. Does anyone have any idea as to what might be causing this problem?

Thanks in advance