Horrible Windows Debug Performance

I'm working with a three-platform heavily modified TGE 1.5 build, and I've been completely on Debug builds for a long time. Recently, I got my weapons working in the game, which are mainly based on Particles for appearance. They are working like a charm on Linux and OSX, but the game is crawling along horribly on Windows. When I hit the trigger I'm the latency (on a local game, no less) goes through the roof, until the game freezes- at least until the projectiles decay. On Mac/Linux, no problems whatsoever, using debug builds, using the same test scenarios.

So I finally broke down and did a release build for Windows- and it's running just like the other two do in debug. This really worries me, because I have been counting on the speed increase from the release build as a final ace up my sleeve to squeeze some real life out of the game.

Has anybody else encountered such a pronounced difference in this? I'm not even sure what to look at to trace this down. I have the profiler running (turning it off doesn't help, btw), and it seems to spend a long time doing the physics calculations compared to the other platforms, which would indicate CPU bound problems, but we're running it on comparable hardware all the way around.

Any clues?