Internet Explorer Concept Search button missing for Data Export and Row Per Obs Data Exports

In Internet Explorer 8, and potentially other versions of IE, the search button doesn't appear when defining a column based on a concept. This happens with Data Exports and Row Per Obs Data Exports. This happens with OpenMRS 1.3.2.00 Build 5653, 1.4.4.00 Build 9695 (web demo) and 1.5.0 RC2 Build 10047.