Well, to be honest, I don't think that's the problem. I have a GeForce 2 MX/MX400 w/TV-out and anti-aliasing isn't causing any problems.
And, I've got some more info for ya. I just did some testing and it turns out that it's a skin that crashes SP back to the main screen. Here's a list of the skins I used when this happened (one custom map installed with five UI/Sound mods, all proven to work ok):
506Easy
82nd PIR.pk3
8th (11 of them)
8thInf (8 of them)
alliedofficers.pk3
Col.pk3
combat_manon.pk3
FI-relic-canucks.pk3
hitler-vip.pk3
japanese_soldiers.pk3
Kompanie3-WaffenSS-MP.pk3
mtv_axis.pk3
navy_SEALS.pk3
panzergrenadier_sniperFIXED.pk3
Random Task's Elite Division v1.0.pk3
Random Task's German Models ver1.1.pk3
Random_Task_Brandenburg_Commando.pk3
Saddam_Hussain.pk3
SEAL_Desert_camo.pk3
SEAL_urban_camoflauge.pk3
SEAL_woodland_camo.pk3
Sniper_Heer_MP_SP-Falpo.pk3
snow soldier.pk3
Titleist-Player-Model-2.pk3
XENO_fallschirmjager.pk3
[MoD] BHD-Ranger.pk3
2ndAirbRangClanSkin.pk3
17thAlliedClanSkin.pk3
101st PIR-MP.pk3
wolf-mans_rangers.pk3
Allied_101's_airborne.pk3
I tested these skins one at a time and they all worked:
2ndAirbRangClanSkin.pk3
17thAlliedClanSkin.pk3
101st PIR-MP.pk3
wolf-mans_rangers.pk3
Allied_101's_airborne.pk3
I'll continue to do this and report which ones work and which don't. I'm kinda tired of it right now, so this info will come later tonight.
