After upgrading JIRA to 4.4.x the JIRA issues Macro does not work as expected if you set some custom fields as columns. It occurs either using the old one or the new syntax. The following error message is logged on Confluence side:

2011-10-16 14:08:00,541 ERROR [http-18050-14] [confluence.extra.jira.JiraIssuesManager] getChannelElement Error while trying to assemble the issues returned in XML format: Error on line 111: The entity name must immediately follow the '&' in the entity reference.
 -- url: /test/PD/1.11+Release+Notes | page: 11123123 | userName: testuser | referer: https://testinstance.com
2011-10-16 14:08:00,544 ERROR [http-18050-14] [confluence.extra.jira.JiraIssuesMacro] throwMacroException java.io.IOException: Error on line 320: The entity name must immediately follow the '&' in the entity reference.

It occurs because there are some custom field options containing the character '&' in the results. Confluence faces the '&' it expects an entity reference on the sequence, but this is just the name of an option of the custom field.

The proposed resolution is to make Confluence able to automatically escape this char from the XML file or improve the error message on both sides.