I have edited this ticket to better explain the issue. Also deleted few unrelated comments (Spark currently invokes the system default browser both on Windows and Linux and not a hardcoded one). Charnigo's URL example added to description.
chongo2002 October 10, 2008 at 3:03 AM
We are also experiencing this problem, URL's that have comma's in them break at the first comma:
URLs with commas break before first comma
example of URL http://www.foxnews.com/story/0,2933,433830,00.html