[huesmann]

I did hold a paper towel and it was sucking but not enough to really hold it there.

Did you do this with the bathroom door open, or closed?

 

[huesmann]

I dunno...if the fan is blowing any air at all, covering it entirely should make the towel stick. My cheapass little Broans will hold one panel of towel covering less than half of the vent. If it can't hold a single panel right in the middle of the vent, I think that's a problem.