Preview Banner mangles URLs

Tried to setup the banner with a referenc to the JIRA 3.4 release notes. Ironcily the banner will not accept the URL format used for Atlassian own webpages. The following HTML was entered into the banner setup;

<CENTER>JIRA 3.4 IS NOW INSTALLED<A HREF=http://confluence.atlassian.com/display/JIRA/JIRA+3.4+and+3.4.1+Release Notes>Review Release Notes Here</A></CENTER>

After saving the setup, JIRA converts the text to the following;

<CENTER>JIRA 3.4 IS NOW INSTALLED<A HREF=http://confluence.atlassian.com/display/JIRA/JIRA 3.4 and 3.4.1 Release Notes>Review Release Notes Here</A></CENTER>

Note that the + in the release notes page URL have been removed. This is making it impossible to create a banner link to the new versions release notes.