Inon strobes give less light when fired via sync cable?

I took my new rig out yesterday for the first time, and was a little surprised at how my strobes performed. For background, this is what I used to shoot:

Olympus C5000 with single Inon Z240 fired via fibre optic

The new setup is:

D200 in a S&S housing with 2 Z240's fired via electronic sync cable (S&S dual 5-pin sync cord).

The sync cord is plugged into the blukhead on the housing *not* marked CONVERTER. With the old and new setup, I put the strobe on the "M" setting.

However, with the old camera, for a given shot, I'd have the single strobe on 1/4 - 1/2 power maybe. Yesterday, I had to put BOTH strobes on the highest power setting in M mode to get adequate lighting. I don't think strobe positioning was the culprit, as I positioned them just outside of the frame and they were aimed correctly. I was shooting WA on 1/60 and with a fairly wide aperture (f5.6 or so).

So, I guess my question is, is it possible that something is setup improperly? Thumbing through the Inon documentation, I see that there are these little things they give you called "TTL Insulating plates" which they say to put in the sync-cable bulkhead. Basically, as far as I can tell, these serve the function of breaking the connection for 2 of the 5 pins. Could this be my problem?

Any help would be appreciated,

-Rob

Make sure the magnet switch is pushed in and locked down...

Make sure the magnet switch is pushed in and locked down...

thanks, I'll try that. I know that it was not pushed down when I took it out the other day. Out of curiosity, what does the button do? I wasn't quite able to understand from reading the manual... In the mode that I was shooting the other day (i.e. via electical sync, mode switch set to M, and the button popped up), what was the strobe doing?