Error when inserting a long url

Issue Summary

First off, thank you for the great module! Works like a champ except when inserting a very long url like:

http://www.amazon.com/gp/product/B0021L8V1Q/ref=s9_simh_gw_p74_d2_i7?pf_...

This causes the watchdog error:
unable to complete Bluga WebThumb request: EntityRef: expecting ';' EntityRef: expecting ';' EntityRef: expecting ';' EntityRef: expecting ';' EntityRef: expecting ';'

If I manually enter the same url into the bluga webthumb site, it successfully creates the image. I've tested it with several long and short urls and can't quite tell if it's due to the length or url encoding. Short clean urls work great with the module.
Any ideas on why this may be happening? Thanks