Dave,
I have been using IE 8 on this computer.  It is just as slow as IE 7 on my other computer.  FireFox is working good. 

Most of wait times were between 5 and 7 seconds on Machinery Talk.  But then I went to Crop talk and the wait times were 30 to 35 seconds.  Stock talk was 10 seconds.  Café was 14 seconds.  Kitchen was 5 seconds.  Boiler was 41 seconds.  The wait time is every time I request the thread list.  There is no wait time when I click an individual thread.

I then fired up FireFox and wait times were between 1 and 2 seconds for all categories.

The problem seems to be with Javascript in both IE7 and IE8.  Do a google search for "javascript slow IE8" and you will see it is a common problem.  I could not find a solution to help you though.

Running Verizon DSL with 1.15 mbps download and 0.36 upload speed tonight.