Cue Sends in Cubase

Hi Folks, can anyone tell me why my cue sends on each track gets turned off, I presume when I close down Cubase 7.5.

I have a project which I use live. The project has all of our songs on it, one after another. The cue sends are used as our IEM and monitor speakers.

The problem occurs when I start up the project all of the cue sends on each individual track needs to be switched on again.

Thanks
John