Jackd kicking ardour out

Hello guy's,

I have an anoying problem when recording, it's pretty new that's why I'm 
thinking maybe it's my machine'performance going down...
Jackd'skicking Ardour out with this message :

subgraph starting at qjackctl-7497 timed out (subgraph_wait_fd=14, 
status = 0, state = Triggered

Comes after a few minutes, doesn't happened if I record a short time. 
Anybody ever saw that here ?

Thanx a lot for helping,

Eric,