EDIT 2: per quick discussion with Token on the pirate chat, it's a Russian OFDM modem.
What I said in chat was that IF it was Russian it was probably some kind of OFDM, however I had not yet had time to look at the signal in software, and I was bothered by the apparent Doppler tone on the wrong side of the data. The Russian systems typically put the Doppler tone above the data, say around 3300 Hz, this one apparently has a Doppler tone (judging by ear) below the data.
I still have not had a chance to look at the signal in detail, however I did get a chance to grab a histogram. I am pretty sure this signal is not a Russian modem, but rather it is MIL-STD 188-110 A/B Appen B, possibly in 39 x 44.44 Bd QPSK or some signal based on that system. Several people (including the Chinese) have come out with modifications to that format that can be hard to discern from the original.
(edit) I have looked closer at this signal, and yes, it is either MIL-STD 188-110A Appendix B, 39 tone, or one of the many slightly modified versions of that signal in use by multiple sources. The Bulgarians are known to use a version very similar to this, however I have not heard Bulgarians on that particular frequency.
T!