Quite a bit ago, this topic was debated here. I think 99leadballoons determined that they did not have to file. Maybe he can chime in here.
If memory serves, I think they were exempt because in accordance with Section 12(g) of the Exchange Act, a company that does not have total assets exceeding $1,000,0000 and a class of equity securities held of record by 500 or more persons doesn't need to register under the Exchange Act and therefore doesn't have to file Form 3's.