RSS Feed Widget not working for complex URL

I was trying to get a RSS feed on my blog from a site with a long URL and it doesn’t seem to be working. The feed source shows up as valid in the various online validators, and I have no problem with other feeds other than these long ones.

Here is the feed I’m trying to pull in (this link, or below):

https://weblogs.macromedia.com/mxna/xml/rss.cfm?query=byCategory&languages=1&categoryId=2

I’m guessing that the ? or the ampersands are being parsed out in some way by the widgets.php code.

Anyone happen to know a solution?