Noticed this issue whilst setting up pyflakes on Snow Leopard:

Error detected while processing function <SNR>66_RunPyflakes:
line   30:
Traceback (most recent call last):
Error detected while processing function <SNR>66_RunPyflakes:
line   30:
File "<string>", line 1, in <module>
Error detected while processing function <SNR>66_RunPyflakes:
line   30:
File "<string>", line 50, in check
Error detected while processing function <SNR>66_RunPyflakes:
line   30:
TypeError: attribute name must be a string