Rogue Trooper - unplayable FPS on Hoppa Chase level

[HangTime]

Currently playing through Rogue Trooper (Steam edition on Win7x64). Everything has been fine up to now, typically around 300-900fps on my i5 @ 4ghz, GTX470 setup.

However, the Hoppa Chase level where you are manning some kind of aircraft turret is literally unplayable from the start - as in it runs at about 1fps at best making it impossible to aim or well do, anything.

Looking on google it seems to mainly affect Vista/W7 64bit systems, but I haven't been able to find a fix. Setting compatibility mode to Win98/ME was suggested, but the Steam version won't run if you do that.

So, does anyone know of a fix for this?
Cheers.

***EDIT***
In case anyone else searches and finds this thread in future, I was able to fix it by setting both Steam client and the game to WinXP SP3 compatability.

 

[HangTime]

Just completed this, my view:

+Reasonable array of weaponry
+GI implants add a bit of character
+Special abilities like setting up turret, hologram projector etc are nice, although to be honest most of the time I just went in rambo style
+Performance is excellent with the exception of the above issue (to be expected due to game age)
+'On rails' sections are nice to break things up a bit, I'm a bit of a sucker for these sort of things
+Salvage system works quite well although you never run out so can just take all upgrades rather than being forced to choose between them

-Graphics are pretty poor for a 2006 game, especially close up textures on vehicles and character models. Even 2004 titles like FC, D3 and HL2 look much better IMO.
-Very contrived approach to enemy vehicles - there always seems to be a bazooka, flak cannon etc handy
-Controls feel a bit fiddly and 'console-portish', e.g. the reuse of the use key for multiple things
-Quite a short game, over in about 6hrs on normal difficulty.