[rt-users] Slowness with old browsers

[Jesse Vincent]

On Thu, Sep 08, 2011 at 01:21:51PM -0400, Josh Narins wrote:
> My company uses a lot of IE7.
> 
> Rendering times for pages are much slower with RT4.0.2 than with RT3.8.8, which we were using last week.

Just at a guess, you're running into issues around the corner rounding many people very much wanted.
If you have a look through the list archives, you should find a discussion of how to disable the IE-specific corner rounding workaround as a first thing to test.