Just did some testing on FAST and found that for 4 of my sites launched since last autumn, only the index pages have been indexed (via free submit). These same sites rank top 5 in Google for main KWs, and two have Yahoo! listings. All are in DMOZ and have good inbound links.
Further testing of some older sites shows that the only pages re-indexed by FAST in past 6 months are those that were listed last year. All new pages added to those old sites have been ignored.
Conclusion - FAST is only indexing one page per site for any new site submitted for free or found through links. This is in line with its PFI, which is on a per-page basis.