I have just had my mkII serviced and out of interest decided to check the time/mileage(its on variable length service intervals) to next service using the reset button . The display comes up but but has no mileage or days. Is it simply the dealer failing to reset the indicator?

Have a nosey through this thread: http://briskoda.net/forums/octavia-ii/service-interval-reset/108931/

In short, it's perfectly normal to be blank for the moment

HTH