Delay compensation problems

[Analogue]

I'm having problems with the ADC. When I switch to another project or song, the ADC stops working from time to time. Not always, of course....but frequently enough to be a p.i.t.a.. Forces me to quit ProTools, log out and back in and then restart the program.
Anybody else having this?
MAC 2.66 quadcore
OSX 10.7.5
PT 10.2 HD 3 (TDM)

Thanks

[WernerF]

Have you tried toggling ADC off and then back on instead of rebooting? I rarely have any problems with ADC not working but when and if it does act up this has always worked.