If you have a recurring mold problem, there's too much moisture in the room.
Prevent the development of the bathroom mold by thoroughly airing out the room after you shower: always leave the door open and operate the ceiling exhaust fan (which should be vented to the exterior) for at least 20 minutes. In warm weather, also leave a window open. A small, oscillating, tabletop fan can speed drying in all seasons; just be sure to plug the fan into a GFI outlet. Hang damp towels to dry in another space for faster drying and prevention of bathroom mold.
To combat bathroom mold, ventilation is key. Learn further ventilation tips with The Money Pit's Bathroom Ventilation Guide.