How are you creating your .map files? It's been found that Q3BSP has trouble compiling .map files generated in Worldcraft/Hammer. Simply loading it and saving it in QuArK can solve this problem.
It has been created using Hammer. A friend made it and send the .map to me. If i try to open it in Quark it complains about switching to Quake 1 and it errors out in some sort of console window.