It sounds like some form of fax or SSTV-type mode, because it sounds like it has a line sync pulse.
I downloaded and registered Multipsk but can't get it going with my Dell desktop's sound card(s). I wanted to use it to analyse a wave file but I can't get the program to do that with its supplied BPSK31 file Messed around for hours trying all sorts of input/output combinations, a loop between the two etc. but gave up in the end. Something to revisit on a rainy day. Fldigi works fine on the PC, but is limited in the modes it can decode.
Damien, i converted those files to .wav and ran them though Multipsk. Those pips are at the 2k mark on the spectrum and the only mode i can get it to trip on is sstv PD290, though this may mean nothing as the signal is pretty noisy. I have also run it though RX-SSTV PD290 with no image. Could try Audacity for a better idea.