Just putting this out there...

If you plan on filing a lawsuit against someone, please check to make sure you're suing the correct person. It will save you a lot of time, money, angry phone calls, and annoying paperwork. It will also prevent you from looking like an idiot. Seriously. Check your bank records before accusing someone of not paying their full amount of rent. OR, simply ask them, and not wait 4 months later to broach the subject again.