Nikon D90 + Ikelite - Strobe Ready Issue?

Hello all - looking for other owners for Nikon D90s in Ikelite housings to determine whether a behavior I'm seeing with mine is normal. I have a DS125 and a DS160 for lighting, connected by a dual TTL cable. Everything will be working fine, but then I'll try to take the next shot and nothing will happen - the camera is powered up according to the LCD display on the top, but it will not bring up the menu, and will not focus or operate the shutter. The small indicator in the LCD on top that usually indicates strobe readiness is gone. I can get things working again by powering off the primary strobe and powering it back up again. There is obviously something wrong with this sporadic issue. But, Ikelite support tells me that if I want to take ambient light shots I can just power off the strobes - well, when I do that the camera becomes unresponsive - strobe ready indicator is off. My question for other owners is this: if you turn off your strobes, will your D90 continue to shoot using ambient light? Or does it insist on getting the camera ready signal from a strobe that's powered on? Thanks,

Pete