N@cro$i$,
I use the optical cable setup to get the strobe to fire. When you buy the strobe it comes with material to cover the internal camera flash (at least mine did from Ryan). The covering allows only infrared light to pass through. Whe the internal flash fires the infrared light is picked up by the optical cable that is positioned on the diffuser. This light triggers the D-2000 to fire.
I shoot everything in Macro, manual mode, and in RAW format. On occasion, when snorkeling, instead of diving, I will use the Program mode for simplicity. Topside, I might shoot either manual RAW or in the Program mode, depending on what I'm doing.
The only problems I've ever had were all operator error. I have accidently set the camera to Super Macro mode, instead of Macro, in which case the flash will not fire. Very disconcerting until you figure out what you've done.
Denny