guiding and mount drift

I am wondering about something.
If a mount is drifting in RA due to slow movement at say 1" per minute and you were guiding a 3 second intervals, which would only see about 1/20" of movement in that 3 seconds and your minimum movement was say .33". Would guiding even see the drift to correct it? Or would it only correct it if there was also a PE in that 3" period that totaled .33" plus the .05" of drift? In other words, would it only add the drift if the PE correction including the drift, amounted to more than the minimum movement?
So, if you were guiding and the PE was smaller than the .33" in the 3 second period, would the drift just continue to go undetected? It seems to me that it would. So drift of a small amount would never really be guided out. Is this a reasonable conclusion?

Floyd,
I do beleive that most guiding software picks the spot it will attempt to keep the guide star on that spot. In other words the point of reference doesn't change so once the error is to the minimum correction setpoint a guide command should be issued. The sample rate nor the cause of the error should make any difference; the guider should always try to return the guide star to the origional reference position.