dude.
listen to your peers. handling issues.
even the kogswell flunkie admits there's stability issues with front racks and loads, he suggests you may want to rerake your fork for stability.
additionally, getting a backpack strap or bungie sucked into your front wheel could cause you to endo. loading a front rig, you need to be careful with all the loose ends.
Just plopping a backpack on a front deck rack IS NOT THE WAY TO DO IT.
GET A BETTER REAR RACK.