Frank,
Although only based on personal experience, fairly normal I think. It certainly happens in the case of a Lexus we run and also the 'shopping' Toyota. The latter - which has discs all round but auxiliary drums for the parking brake- often gets used only about once or twice a week and in the interim sits on a flat drive with no handbrake on but parked in gear. My tame auto engineer ( nephew) tells me this is not a major problem- subject to the proviso that if the car is one fitted with traction control and or ABS and the 'stick' is severe, the sudden resistance/ release of pulling away can upset the sensors.
In the case of my 4/4,I've had a similar thing happen when I've washed the car, dried it off, put it in the garage and then come back to it abpout 5-6 days later.
On the other hand, I had the car in a 'Carcoon' for a couple of months last winter and it didn't happen then, so to me at least that points to the issue definitely being one of damp/ rusting discs sticking and needing to be 'cleaned off' by a hard application as soon as the car is in motion
