Red Orchestra via Steam

Salut a tous
Voila je viens d'aquérir du jeu Red Orchestra avec Steam. Je l'ai acheté et installé avec succes, mais, lorsque je le lance, tout se ferme et un message m'apparait dans une fenetre:
Le voici:

Nom de la fenetre: Err. Critique

Build RedOrchestra_Build_[2005-11-27_10.48]

OS: Windows XP 5.1 (Build: 2600)
CPU: AuthenticAMD Unknown processor @ 2212 MHz with 1023MB RAM
Video: RADEON 9800 PRO (6648)

General protection fault!

History: CheckTag <- LoadSummary <- ULinkerLoad::ULinkerLoad <- CheckTag <- LoadSummary <- ULinkerLoad::ULinkerLoad <- CheckTag <- LoadSummary <- ULinkerLoad::ULinkerLoad <- CheckTag <- LoadSummary <- ULinkerLoad::ULinkerLoad <- CheckTag <- LoadSummary <- ULinkerLoad::ULinkerLoad <- CheckTag <- LoadSummary <- ULinkerLoad::ULinkerLoad <- CheckTag <- LoadSummary <- ULinkerLoad::ULinkerLoad <- CheckTag <- LoadSummary <- ULinkerLoad::ULinkerLoad <- CheckTag <- LoadSummary <- ULinkerLoad::ULinkerLoad <- CheckTag <- LoadSummary <- ULinkerLoad::ULinkerLoad <- CheckTag <- LoadSummary <- ULinkerLoad::ULinkerLoad <- CheckTag <- LoadSummary <- ULinkerLoad::ULinkerLoad <- CheckTag <- LoadSummary <- ULinkerLoad::ULinkerLoad <- CheckTag <- LoadSummary <- ULinkerLoad::ULinkerLoad <- CheckTag <- LoadSummary <- ULinkerLoad::ULinkerLoad <- CheckTag <- LoadSummary <- ULinkerLoad::ULinkerLoad <- CheckTag <- LoadSummary <- ULinkerLoad::ULinkerLoad <- CheckTag <- LoadSummary <- ULinkerLoad::ULinkerLoad <- CheckTag <- LoadSummary <- ULinkerLoad::ULinkerLoad <- CheckTag <- LoadSummary <- ULinkerLoad::ULinkerLoad <- CheckTag <- LoadSummary <- ULinkerLoad::ULinkerLoad <- CheckTag <- LoadSummary <- ULinkerLoad::ULinkerLoad <- CheckTag <- LoadSummary <- ULinkerLoad::ULinkerLoad <- CheckTag <- LoadSummary <- ULinkerLoad::ULinkerLoad <- CheckTag <- LoadSummary <- ULinkerLoad::ULinkerLoad <- UObject::StaticFindObject <- UObject::StaticAllocateObject <- (BoolProperty ReturnValue) <- UObject::StaticConstructObject <- ULinkerLoad::CreateExport <- (ReturnValue 227569) <- IndexToObject <- ULinkerLoad<<UObject <- (LinkerLoad Package.LinkerLoad 227569)) <- UStruct::Serialize <- (Function ROInterface.ROMainMenu.NotifyLevelChange) <- UFunction::Serialize <- LoadObject <- (Function ROInterface.ROMainMenu.NotifyLevelChange 227569==227569/812828 227560 131) <- ULinkerLoad:reload <- LinkProperties <- UStruct::Link <- UState::Link <- UClass::Link <- UStruct::Serialize <- (Class ROInterface.ROMainMenu) <- UState::Serialize <- UClass::Serialize <- (Class ROInterface.ROMainMenu) <- LoadObject <- (Class ROInterface.ROMainMenu 227569==227569/812828 79382 1143) <- ULinkerLoad:reload <- PreLoadObjects <- UObject::EndLoad <- UObject::StaticLoadObject <- (Core.Class ROInterface.ROMainMenu NULL) <- UObject:rocessEvent <- (CinematicPlayer ROintro.CinematicPlayer, Function UnrealGame.CinematicPlayer.Fire) <- UObject::ScriptConsoleExec <- (CinematicPlayer ROintro.CinematicPlayer) <- UPlayer::Exec <- UViewport::Exec <- UWindowsViewport::Exec <- UInput::ExecInputCommands <- ExecAlias <- UInput::Exec <- UViewport::Exec <- UWindowsViewport::Exec <- UInput::ExecInputCommands <- UInput:rocess <- UEngine::InputEvent <- UWindowsViewport::CauseInputEvent <- UWindowsViewport::UpdateInput <- UViewport::ReadInput <- APlayerController::Tick <- TickAllActors <- ULevel::Tick <- (NetMode=0) <- TickLevel <- UGameEngine::Tick <- Level Sans titre <- UpdateWorld <- MainLoop <- FMallocWindows::Free <- FMallocWindows::Realloc <- 0013FF18 0 FArray <- FArray::Realloc <- 0*2 <- FMallocWindows::Free

Merci de vos aides...

j'ai déjà eu ce problème (je suis un ancien joueur de Red Orchestra). Essaye de désactiver anti-virus et pare-feu, moi ça a marché.