I think your problem lies in the fact that you're not escaping URL-special characters (ie, probably ';', though I don't remember off the top of my head). I don't really know PHP but I have to believe they have a better way of building a query string than how you're doing it. At the very least, I'm sure PHP supplies a function to URL-encode data. Use that.

bbfu
Seasons don't fear The Reaper.
Nor do the wind, the sun, and the rain.
We can be like they are.