Should brake pads rest against disc?

The first time that I put the bike up on a paddock stand to check the chain I noticed that the rear pads were binding a little on the disc. I could spin the wheel but it wasn't free-turning. Tried adjusting the brake pedal but the pads and piston stayed resting against the disc. After my next ride (20 miles in the wet using both brakes as normal) I felt the disc - stone cold. I did a quick clean anyway - took out the slide pins, cleaned shafts, pins and re-greased; pumped the piston out to reveal about 3mm of shiny metal, scrubbed with brake fluid and pushed back in (using a lot of finger pressure); cleaned the pads' mounting bar; re-assembled. First press of the brake pedal and pads are back resting against the disc!

1) Is this resting state normal?
2) Or do I need to diassemble completely, clean piston, shaft and replace seals?
3) Should the piston slide quite freely in the shaft after servicing?

Any sound advice would be appreciated. It's a K3 pointy with single piston BTW.

[Spikenipple]

Yeah it's quite normal for the pads to slightly drag on the disc, as long as it's not hard to turn the wheel or stopping the wheel as soon as you've spun it. If you can push the pistons back in by hand, they're fine.

[muzikill]

s'normal - if they werent resting just think about the extra time it would take for them to engage the brake disc, considering its a motorbike it would get you in a seriously bad spot & cause a accident. Its fine for cheap mountain bikes tho! - Its also normal to hear it 'grind' when pushing the bike around especially after leaving the bike out in all weathers. Like has been said you would know if there was a problem if they were seized.