I am using manual flash on camera and strobes - no TTL at all. So the sync settings above work for me. I don't use TTL at all (strobes won't do it - YS02's) so maybe you have some setting for TTL hanging around in the configuration. Using my strobes, I used the above settings and did test shots in the mirror when testing the settings on the strobes to sync. I am not familar with the Inon's so I can't say what is there.
From the doc link I sent and bear in mind I don't use TTL:
Flash Mode:
Manual:
Has the advantage of longer camera battery life, no shutter lag and minimal recycle time. Press OK to see the SCP, select flash with the arrow keys, press OK and use the arrow keys or dial to select "Manual Value", press OK. Back at the SCP, just underneath the flash mode is the manual flash power, select this and choose 1/64 (the minimum).
TTL:
Press OK to see the SCP, select flash with the arrow keys, press OK and use the arrow keys or dial to select "Fill In", and press OK.
I force the flash on all shots (camera and strobes) and adjust the power on the strobes or even turn them off though I don't like doing this underwater too much. This is not the most efficient way to control strobe lighting as it requires manually changing everything.
From the doc link I sent and bear in mind I don't use TTL:
Flash Mode:
Manual:
Has the advantage of longer camera battery life, no shutter lag and minimal recycle time. Press OK to see the SCP, select flash with the arrow keys, press OK and use the arrow keys or dial to select "Manual Value", press OK. Back at the SCP, just underneath the flash mode is the manual flash power, select this and choose 1/64 (the minimum).
TTL:
Press OK to see the SCP, select flash with the arrow keys, press OK and use the arrow keys or dial to select "Fill In", and press OK.
I force the flash on all shots (camera and strobes) and adjust the power on the strobes or even turn them off though I don't like doing this underwater too much. This is not the most efficient way to control strobe lighting as it requires manually changing everything.