Re-Enable Java Plugin in Firefox 11 to Resolve UIS/HOD Issue
Firefox 11 is disabling Java plugin versions that are below version 1.6 Update 31 or between 1.7.0 and 1.7.2 for Windows computers only. This affects the use of Host On-Demand (HOD), including UIS, due to its Java requirements. A resolution has been found for this issue as of April 9, 2012.
Instructions to re-enable the Java plugin are available here. Only someone with administrative rights can perform this task. Mac OS X computers are not currently affected by this Firefox update.