Google Chart API - "Request-URI Too Large", but length well below 2048

I have a strange problem with Google Charts API.

According to the docs, the "GET" limit is 2048 bytes, but I have this one link I created that is well below the limit (1663 bytes) and still chokes the server with a "Request-URI Too Large" error.

Here's the link (check "view source"): broken chart

I'm guessing that it's not really a size problem, but rather some kind of parsing problem in the Google Chart API..?

I have implemented the "form" fallback (to enable 16K requests), but I only want to use this method when th开发者_如何学Pythone request gets bigger than the allowable 2K.

Any ideas?

Thanks, Sebastian

Maybe lose the 1-300 chxl parameter - it doesn't display well at all. And check your chof=validate. I'm not sure what it does but if I remove both of those things your chart appears perfectly.