This bug was reported in Version 2.0, and was present in Version 1.0, Version 1.1 and Version 1.2. It was fixed in Version 2.1.
Any URLs linking to nodes with titles containing one of the following characters could produce unpredictable results, due to Cloud Wiki's HTML generator not escaping these characters in URLs: "#", "/", "?", "&", "+", and "="
This is an entry in the bug list.