Forum Block Sidebar refreshes forums extremely slow?

[Pyreflame]

Hi,
I've got a recently installed version of VB (4.1.0, non-CMS), and the forum sidebar is making the forum page *extremely* slow to load. It takes 10-15 seconds for the forum page to load, whenever the forum sidebars' cache interval is set to update. I've tried several VB optimizations, but it still does not seem to impact how fast the page loads when the sidebar needs to update itself. I'd prefer that whenever users refresh the page, they see the most recent posts, so i'd like the cache interval set fairly low, but if i do, it kills the refresh time.

Any ideas how to speed this up, or what might be causing it to slow down? The forum isn't being used publicly yet, so i'm pretty much working with a fresh install, aside from adding a style to the forums.