Pathauto punctuation removal doesn't work properly with taxonomy term

Hi,
All I got stuck in a big problem at time of url creation when i posted a topic like abc?%* then i got unexpected path like abc039 however i have cleaned all punctuation mark from autopath alias settings.
I am using path pattern for taxonomy term like topic/[cat] and i have also checked the logic behind punctuation cleaning but it worked properly when i run this code .
All suggestion are welcome here.
Thanks in advance.