Digital BW, The Print

I tend to run a nozzle check at the beginning of a day's printing and I've been noticing that 
my R220s have started running what sounds like a brief cleaning cycle before running the 
nozzle check.  I hadn't paid much attention to it in the past and assumed it was because I 
was going long periods between prints (5-7 days) but today one of them just ran the 
cleaning cycle before the nozzle check and I had just run it yesterday.  Anyone else 
encountering anything similar.

Robert