trouble using three logitech cam in image acquistion

I'm try to use three logitech cam: 1 QuickCam Communicate Deluxe and 2 c190, to work simultaneously during and image acquasition script. The preview shows each image perfectly, but during the script the following error message apear:

"Error using imaqdevice/start (line 96) winvideo: Image acquisition device is not accessible. A device attached to the system is not functioning. Make sure no other objects or applications are accessing the same device."

the script had worked with only one cam connected but not with more then one connected.

I've tried to put "pause(x)" between each "start(vid)", and also tried to change each cam drive to UVC drive. none of which work.

what else can be done?

thank you for the help. itai