FPS Deterioation
Ok..heres my situation...
I've had tremulous (and my computer) for about a year and a half now. When i first started playing i used to get a lovely constant 90fps everywhere. Slowly i noticed the fps dropping on more complex areas ie.stairwell in nexus, near transparent objects, when loads of are in the in the room(u get the idea). At first it was ok... just droping to about 50fps..barely noticble, but mroe recently it has got worse (the last 5 months or so), dropping ot 20-30 fps (which is really annoying when dretching

). I still 90 fps in the less complex areas but now the fps fluctuates a lot.
I havent changed any settings(that i know of(almost all settings on high)).
I dont thinhk i have a virus in my pc. Loading times just take a second longer (barely).
here's my system specs:
BasicWindows XP Home Edition Service Pack 2
Processor: Intel(R) Pentium(R) D CPU 2.80GHz (2 CPUs)
Video Card : RADEON 9550 (256mb)
RAM : 1.00GB
HDD: 70GB out of 97GB used
Detailed Operating System: Windows XP Home Edition (5.1, Build 2600) Service Pack 2 (2600.xpsp_sp2_gdr.070227-2254)
Language: English (Regional Setting: English)
System Manufacturer: System manufacturer
System Model: System Product Name
BIOS: Rev 1.00
Processor: Intel(R) Pentium(R) D CPU 2.80GHz (2 CPUs)
Memory: 1024MB RAM
Page File: 501MB used, 1963MB available
Windows Dir: C:\WINDOWS
DirectX Version: DirectX 9.0c (4.09.0000.0904)
DX Setup Parameters: Not found
DxDiag Version: 5.03.2600.2180 32bit Unicode
Card name: RADEON 9550
Manufacturer: ATI Technologies Inc.
Chip type: ATI Radeon Graphics Processor AGP (0x4153)
DAC type: Internal DAC(400MHz)
Device Key: Enum\PCI\VEN_1002&DEV_4153&SUBSYS_00021002&REV_00
Display Memory: 256.0 MB
Current Mode: 1024 x 768 (32 bit) (60Hz)
Monitor: Plug and Play Monitor
Monitor Max Res: 1600,1200
Driver Name: ati2dvag.dll
Driver Version: 6.14.0010.6727 (English)
DDI Version: 9 (or higher)
Driver Attributes: Final Retail
Driver Date/Size: 9/29/2007 02:06:18, 268800 bytes
WHQL Logo'd: Yes
WHQL Date Stamp: n/a
VDD: n/a
Mini VDD: ati2mtag.sys
Mini VDD Date: 9/29/2007 02:06:00, 2456064 bytes
Device Identifier: {D7B71EE2-0213-11CF-F569-0820A1C2CB35}
Vendor ID: 0x1002
Device ID: 0x4153
SubSys ID: 0x00021002
Revision ID: 0x0000
Revision ID: 0x0000
Video Accel: ModeMPEG2_C ModeMPEG2_D ModeWMV8_B ModeWMV8_A ModeWMV9_B ModeWMV9_A
Registry: OK
DDraw Status: Enabled
D3D Status: Enabled
AGP Status: Enabled
DDraw Test Result: All tests were successful.
D3D7 Test Result: All tests were successful.
D3D8 Test Result: All tests were successful.
D3D9 Test Result: All tests were successful.
I defragged a few weeks ago but didnt really seem to affect performance.

Any help on how ot get my FPS back to a reasonable standard would be much appreciated!
If u need any more information about my PC then just tell me.
Computer Experience: Average