pronterface shlex.pyc error, what to do?

Hello everyone,

I've just finished a Mendel-build after months of problem-solving. I use pronterface and played a bit with the axes, even did a 5mm extrude from pronterface. But now I try to load an STL...and no matter what STL I load, I get:

Quote
pronterface console
Skeinforge execution failed.
Traceback (most recent call last):
File "pronterface.py", line 1254, in skein_func
File "shlex.pyc", line 279, in split
File "shlex.pyc", line 269, in next
File "shlex.pyc", line 96, in get_token
File "shlex.pyc", line 172, in read_token
ValueError: No closing quotation

What's wrong and how do I fix it? Is this a python piece of code that's missing some kind of separator? I don't know Python at all...I hope someone can help me out! Thanks!