Custom Map Vehicles do not work in sigle player, very glitchy in multiplayer

I have a problem with custom drivable vehicles that are embedded in a map’s bsp file. If you don’t know what I’m talking about, I’m referring to stuff like the drivable volvos in rp_hometown1999 and rp_amsterville.

In singleplayer, the vehicles spawn without textures. Not a purple/black checker pattern, just no textures at all, as if someone took the color tool out and made it invisible. I know the car is still there, since it can be grabbed with the physgun and can be removed. The vehicles can also be entered, but everything except the HUD goes black when I do enter the vehicle, and then I can’t exit them.

When I create a server, the vehicles are completely visible, custom textures and all, but the wheels are turned at a 45-degree angle. when I enter the vehicle and try to drive it, it can only accelerate, brake, and reverse; I can’t turn at all, and the wheels stay locked at the 45-degree angle.

So I figured there was something wrong with my lua scripts or something. To test it, I went to my vehicles menu, and then I spawned an identical blue volvo from GMOW. This one worked perfectly, it can still turn and everything.

I know this has nothing to do with my mods. I’ve had this problem for a long time, and after several reinstalls and clean-ups of my custom content, the glitch remains there. The last I can remember those vehicle working were before the episode 2 engine update.

I talked to some friends and nobody else seems to have this problem, so it can’t be a problem with the map file because they have no problems with the map.

Oh, and here are some screenshots of the bug:

SINGLE PLAYER:

http://img56.imageshack.us/img56/4498/rphometown19990000.jpg
http://img35.imageshack.us/img35/575/rphometown19990001.jpg
http://img113.imageshack.us/img113/1318/rphometown19990002.jpg
http://img103.imageshack.us/img103/1862/rphometown19990009.jpg
http://img56.imageshack.us/img56/663/rphometown19990010.jpg

MULTIPLAYER:

http://img6.imageshack.us/img6/9919/rphometown19990014.jpg
http://img229.imageshack.us/img229/6263/rphometown19990012.jpg

for the screenshot below, the volvo on the left is spawned from the spawn menu, and the one on the right is embedded in the map file.

http://img33.imageshack.us/img33/5071/rphometown19990017.jpg