Yeah, just sounds like the pistons getting stuck!
Not sure how you get the pistons out the 05 levers, I've only ever had 04s! But pop it out if you can, give it a proper clean up and oil it, then carefully sand down the bore in the lever body with some very fine sandpaper, refit and try. Just pop the lever together and pull it a few times, shouldn't have to bleed it every time you test it!