Ok,in md2 export script,if i have more than 1 texture for a script,i get an error message that i have more than 1.The error window chases the mouse,if i press OK it reappears.I have to restart Blender to use it again.Are you guys kidding me??Who ever wrote that script?Why write lines of code that makes an error window chase the mouse??Instead that guy could think that i might want to export to another format or just continue using Blender?
And are you guys thinking of making same style GUI for all the exporters someday?I mean it looks like Blender is sheet of different coloured papers glued together.
rant over 
bestseclub.
I tested the script & if you follow instructions it works.
however it appears not to export textures.
It may actually be able to export the file with uv map data.
then when you import it into your chosen program,
it should be easy to re map the textures.
I did recreate your error exactly, this was due to limitations within the script.
& a little user error. that is not setting up everything properly for export.
Painful I know, you may want to check the Quake forums to see how people are getting around the scripts limitations, or if they is another script out there that works better.
for the tech information on the file format.