Using the latest source from git hub, I am unable to save renders:-
"
INFO: DirectLight: Rendering pass 1 of 1...
INFO: DirectLight: Overall rendertime: 0.234052s
INFO: imageFilm: Flushing buffer...
INFO: imageFilm: Done.
INFO: Render completed!
ERROR: Environment: Don't know how to create ImageHandler of type ''!
INFO: imageFilm: Flushing buffer...
INFO: imageFilm: Done.
"

If I click the 'Quit Yafaray' button on the Qt render window, then choose "Save" to save the rendered image, something, presumably Qt, crashes. When I 'Force Quit' 'Yafaray Save Image' Blender quits.

I tried running it in gdb and got this backtrace. Don't know if it is helpful:-
"
INFO: imageFilm: Flushing buffer...
[Thread 0x7fffde266910 (LWP 12298) exited]
[Thread 0x7fffdda65910 (LWP 12299) exited]
INFO: imageFilm: Done.
[Thread 0x7fffdeac7910 (LWP 12297) exited]
INFO: Render completed!
[New Thread 0x7fffdeac7910 (LWP 12300)]
[New Thread 0x7fffd7fff910 (LWP 12301)]
[New Thread 0x7fffd77fe910 (LWP 12302)]
[Thread 0x7fffdeac7910 (LWP 12300) exited]
[Thread 0x7fffd77fe910 (LWP 12302) exited]
[New Thread 0x7fffd77fe910 (LWP 12303)]
[Thread 0x7fffd77fe910 (LWP 12303) exited]
[New Thread 0x7fffd77fe910 (LWP 12304)]
ERROR: Environment: Don't know how to create ImageHandler of type ''!
INFO: imageFilm: Flushing buffer...
INFO: imageFilm: Done.
[Thread 0x7fffd77fe910 (LWP 12304) exited]
[Thread 0x7fffd7fff910 (LWP 12301) exited]
"
From here the 'Save Image' window hangs until I force quit:-
"
Program terminated with signal SIGKILL, Killed.
The program no longer exists.
(gdb)
"

Ubuntu 9.10 64 bit
Blender 2.49.2
Yafaray 0.1.2 beta
libqt4.5.3really4.5.2