Bought a new RER in July 2006 which is still under warranty. Model No. 281223BVE. Took it in for routine service early this spring for tune-up, new mulch blade, drive disk, etc. Since that service, I have returned it to the selling dealer twice for an operational problem that only happens after the mower is hot. When I finish mowing my backyard, I have to exit the mower to open a gate for another section of the yard. When I get back on the mower and restart it and shift into any forward speed, there is no forward motion and no reverse either. However, repeated shifting into reverse usually works although it is at a slower speed. The selling dealer did not find any problems during two followup visits. The mower is now at a larger dealership and they cannot get the drive issue to duplicate. Snapper Tech Support is now involved but neither Snapper nor the third dealer can diagnose the problem. When the mower is cold, none of these operational problems happen. All technical assistance is welcome. Thanks.