That sounds rather bad, something must be possible to find..
I get the results below with a rather similar rig (1,5 years old now - waited for BoB news but decided to buy anyway in december 2006 - good choice!):
From the Fraps log:
2008-05-12 21:44:00 - il2fb
Frames: 10774 - Time: 155469ms - Avg: 69.300 - Min: 24 - Max: 117
That is with 4.09b1 (latest dll:s), every thing maxed out that I know of
Open GL 1280x1024 (all on high/perfect etc)
Nvidia driver forced to 16x Aniso and 16qx Anti Aliasing + AA Transparency
Forest=3
LandShading=3
Water=4
etc...
Have you tried this?:
conf.ini:
ProcessAffinityMask=2
Nvidia 3D options "overrides" for il2fb.exe:
Texture Filtering - Anisotropic sample optimization = on
Texture Filtering - Trilinear optimization = off
Vertical sync = force off
Some say the above can help...
My once smoking rig - in december 2006 it was hot
Intel Core 2 Duo E6700 (@3.0Ghz - 1200Mhz FSB)
Asus Striker Extreme NForce680i SLI MB
Asus GeForce 8800GTX 768Mb
2 x 1Gb Corsair PC6400 XMS2 XTREME CAS4 @900Mhz 4-4-4-15 2,1 Volt
1 x RAPTOR 150GB + 2 x Raptor 74Gb (raid 0) + Hitatchi T7K500 320GB
Creative SB X-Fi Xtreme Gamer Fatal1ty Professional
Zalman CNPS9700 Cpu cooler
Antec TruePower Trio 650W
Antec P180B Chassis
Dual boot - Windows XP SP3 and Vista64 Ultimate
PS - running XP SP3 for IL2 naturally... Vista makes me fall asleep gaming.