I just added a bunch of wma files to Picard 1.3.2 and got the following error.
Interesting is, that some other wmas of another album got recognized correct.
The files are now marked with the red "no way" icon on the left.

D: 20:31:56 Loading file u'X:\\Users\\xxxxxx\\Music\\Musik_Mp3
Good Charlotte
The young and the Hopeless
04 WONDERING.wma'
E: 20:31:56 Traceback (most recent call last):
File "picard\util\thread.pyo", line 46, in run
File "picard\formats\asf.pyo", line 167, in _load
TypeError: coercing to Unicode: need string or buffer, int found

E: 20:31:56 Traceback (most recent call last):
File "picard\util\thread.pyo", line 46, in run
File "picard\formats\asf.pyo", line 167, in _load
TypeError: coercing to Unicode: need string or buffer, int found