Are you absolutely certain that the entire URL is being posted to twitter? Is it possible that some filter is interpreting the “&” character and stripping off the remaining URL before you post it to twitter?
Do you have a log of what is being transmitted to twitter? Are you transmitting through any proxies which could potentially be stripping the data off? Is twitter the only site with which this problem is occuring? I can’t reproduce the problem, including posting the URL you listed, but I am URL encoding “&” to “%26”. By definition (see http://apiwiki.twitter.com/Things-Every-Developer-Should-Know#5Parametershavecertainexpectations) tweets are supposed to be URL encoded before transmitting to twitter, so I don’t understand what you mean by URL encoding. If you want the “&” to have meaning within your tweet (regardless of whether it’s in a URL or just text), you MUST convert it to %26 otherwise it will appear to twitter as a variable on par with source, geo, status and in_reply_to_status_id. If you are not URL encoding the tweet then start doing so. -- -ed costello