Firefox performance on Fedora vs Win32

[Joe Desbonnet]

Right now I don't have hard evidence for this, and I'm not exactly
sure the best way of proving it:

On the same hardware (Thinkpad T41p, 1.5GB RAM) it *seems* to me that
Firefox is far more responsive for web applications than the exact
same version of Firefox (1.5.0.4) on the exact same computer running
Fedora Core 5.

I notice this in particular for OpenCMS: a content management system
web application that makes heavy use of Javascript in its backend.

Before I invest time getting hard numbers for this: is this a known
issue? If not what could be causing this (apart from my imagination
:-)? My guess that it's javascript related. Or perhaps Firefox page
rendering is much faster in Win32?

Joe.