The revamped jiraissues macro in 2.10 is breaking layouts that use columns. When a jiraissues macro is embedded in a page column:

{section} {column:width=50%}
First column {jiraissues:url=http://test.jira.com/sr/jira.issueviews:searchrequest-xml/temp/SearchRequest.xml?pid=10226&sorter/field=issuekey&sorter/order=DESC&tempMax=1000}{column} {column}
A second column{column}{section}

The jiraissues macro in 2.9.2 used to do its best to fix within the given constraints.

In Confluence 2.10, the jiraissues macro grabs as much page width as it can, pushing the second column off the screen. If the window is resized to include both the (huge) jiraissues and the second column, and refreshed, the jiraissues macro grabs still more space, pushing the second column off the screen again.