Canon G9 out of Sync

Hi all,

I have a new Canon G9 with Ikelite housing and an old DS-50 strobe.

The strobe was upgraded in the US for it to work with the camera TTL.

But i have a sync problem, when i'm taking a picture of the strobe, the picture isn't burnt (See attachment).

Those are the camera ext. flash settings:

Flash Mode: Auto

Flash exp. comp: +0

Shutter sync: 1st-curtain (I tried '2nd-curtain' as well)

Slow synchro: off

Safety FE: on (I tried 'off' as well)

Do you know what can be the problem?

Should it be burnt ?

Anyway, isn't that dangeraous for the sensor?

Uh, the strobe in that picture is definitely overexposed. How much brighter would you expect it to be?