Yep, that's a problem.
Here's what I have done to free "slated solid" zippers.
Spray them with a good penetrating fluid. I use TC-11, but Balistol has worked also. Let it soak for a dayor 2.
The get a hot water hose and run hot water on the zip closure for a while.
Between these 2 "treatments" I've been able to get most zippers working again.
Use a short piece of line on the closure hook (not the zipper pull as you will pull that off).
Jerk the line in both directions with the hot water flowing on the zip closure.
Works most of the time.
Then lube the zipper with soap or zipper lube to prevent it happening again.
Hope this helps,
Last edited by Roger; 8th August 2010 at 10:13 PM.