MAGLITE D- Cell : Push button off/on switch is stuck in the on(down) position and won't release to the up(off) position. Any suggestions? Thx!

Hahahahahaha, who still has the rubber cover? That thing is gone after the second use. They need a better switch on maglites.

You can try this short of replacing the switch. Purchase a can of spray electronic cleaner such as CRC QD Electronic Cleaner. Remove the batteries from the Maglite. Pry off the rubber cover from the switch by grasping with thumb and forefinger, squeezing and pulling. Spray the on/off switch throughly with the cleaner. Also spray inside the Maglite with the cleaner making sure you hit the switch from the underside. It will dry very quickly but wait at least 5 minutes and then reinstall the batteries. If this does not work you will need to replace the switch. Go here to order the switch and here you will find detailed instructions on replacing the switch. You will need a 5/64 Hex wrench to replace the switch. http://www.maglite.com/pdf/CustServ/CD_switch_repair_8_0410212004719392.pdf
If this is the wrong Maglite go here and choose the correct flashlite. http://www.maglite.com/custserv.asp

Try gently pulling up the rubber cover for the switch. use a butter knife to gently pull it free. Then you should be able to see the switch button itself. Try a *small* drop of a plastic safe lubricant. Or try a small spray of silicone lubricant. This should free it up. If not Mag Light has replacements, and they do offer a lifetime warranty. Here are the switch replacement instructions