Here is the response from Tech Support, to which I replied that the issue (at least for me) is ongoing (has anyone had it resolve yet?):
Recently you requested personal assistance from our on-line support center. Below is a summary of your request and our response. Please reply to this message if your issue has not been resolved.
Thank you for allowing us to be of service to you.
Subject system is changing saved URLs and generating errors
Response Via Email (Michael) 05/04/2013 02:28 PM
Thank you for contacting Ancestry.com in regard to a problem with saved URL's on Ancestry.
We apologize for any frustration this issue may have caused and appreciate your feedback. We have forwarded your message on to the proper departments for consideration.
For information regarding additional methods of submitting feedback, please visit the following URL: http://ancestry.custhelp.com/app/answers/detail/a_id/970/
If you need additional assistance, please feel free to reply to this message or contact us by phone at 1-800-ANCESTRY (1-800-262-3787) from 10am to 10pm EST, Monday through Sunday.
Customer Solutions Associate
Customer By Email (Rebecca) 05/03/2013 12:57 PM
Hello - the system is messing up saved URLs when creating an Ancestry-generated link for user-created sources. Here is a link to a message chain I started this morning, describing the problem, with attachments showing the issues (including from others who are experiencing the same problem with their own user-generated sources): http://boards.ancestry.com/topics.ancestry.ancsite/12777.2.1...
Thanks for looking at this.