Severe texture corruption can cause textures on the level to appear as a banana stating that you are a poor player. The exact cause of this problem is unknown.
This is not exactly a new problem.
I belive i know who was responsible for making this. I recall *** telling people to download a certain map then type a certain cmd in console. It never worked on q2 becuase i was duped into doing it and never got the joke. But the end result was to delete/reboot/reload.
I ams sure you know about this, just trying to help ya bro . I would say more but not public. This was done in feb/march 2003 while playign on e3rrt server. Whish i could find the screenshot, it might be the older q2 folders
among 1000's of tga. (or whatever the file ext is)