A blog I used to follow -- Irreverent Freelancer by writer friend Kathy Kehrli -- was just resurrected in order to give a warning about a deadbeat client: Q2A/Bill Smith Group, which changed its name to QBS Learning.
It sounds like there was an all-too-convenient "merger" right around when payment was due. Funny when the timing works out that way, isn't it!
In any case, Kathy is still owed more than $1,200 plus interest. She even offered them a steeply discounted settlement if they could pay in full right away... Nothing.
Sounds like she's not the only one, either. Visit her blog post on the Q2A/Bill Smith Group a.k.a. QBS Learning for the full story, as well as links to a thread with more writer complaints.