'#size' and '#maxlength' at line 600 and 601 of seowatcher.module are setted to 40, which is too short for some websites URL (my silly french site URL is 41 characters long...)
I suggest you set them up to 60 (this is what i did on my personnal copy of the module) or more ? I think some are checking for internal pages which could end in long URL ?
I didn't check for competitors site. Maybe the same ?

I don't know if my request is done the good way, cause I'm new to Drupal.

Thanks

Philippe Hubert