I've got a pair of 2001 Time Atacs which up to now lived up to their reputation of being incredibly reliable. Bearings are still smooth, and the one time I've opened them up (this week) the grease around the axle was still pristine.

Suddenly though the left pedal had become difficult to unclip from. I need to rotate my foot much further than usual to unclip, and even then the mechanism feels 'sticky' and unwilling to release the cleat. Nor is this problem consistent- sometimes the unclip is 'sticky' and sometimes it pops out normally for the same side of the pedal.

It doesn't appear to be the cleats- they are only a couple of months old and they haven't shifted position in the shoe. I've tried unclipping the plastic covers over the springs- they look clean and I've lubed them.

Has anyone encountered this? Can you suggest anything further to try, or is time (heur heur) for new ATACs?