-EDIT- Found a solution. Ran in dxlevel 60 and named maps end prefix to "_dx60". Ran in console with regular name and all problems were fixed.

This is not a solution, this is bad workaround. Run with -dxlevel 90 and rename the maps back.

This only leads to a black screen.

If it works for him then it's a solution and telling him to just change it all back isn't exactly being too helpful.

What sort of hardware do you have, BigBadZombie?

Ubuntu Linux 11.04 i386 with Wine. When I run retail Half Life 2 it says i have DirectX 8.1.

Play on Windows. Playing an unstable build on non-native system only decreases the build's stability.

Try to look if it runs better on a newer Wine release

What did you write in the console?