Hard to diagnose from over the waters really but here's some ideas

Firstly, its worth noting that the new version of the forums are twice as 'graphically instensive' as the original layout. The first version, I was very conservative - not knowing how much bandwidth we would eat up. Because of this, if your PC is quite low spec or your internet connection is on a go-slow, then it will struggle sometimes to load the pages at a decent speed.
I know for certain that when you are connected to IA, you aren't generating any errors on the server - so it is purely down to performance - and it would be my guess its the internet connection. I had the same only last night - but I know for a fact my Broadband connection was on a go slow

The "Hula" effect is an interesting one though .... once the page is loaded and you are scrolling and getting the 'waves' it sounds like its your PC that is the issue (on the premise that your browser is drawing from the cached files).
Which Browser are you using? Internet Explorer?
How much Disk space do you have allocated to temp internet files?
When you get the 'wave' is your hard disk going nuts?
That will do for starters
