Can't load drivers into preboot configurations

After having upgraded to 7.5, I no longer can add drivers to the preboot configurations. When I try, the java loads and I can browse to a folder containing PE4 drivers, but no files appear in the browser. I figured maybe that's just a display bug or something, so I simply select the folder and try to add those. After a time, the dialog errors out (DADriverEditor.aspx). Looking in the SMP logs, I see this:

<event date="12/03/2013 08:32:38.0258444 -07:00" severity="4" hostName="myserver" source="Altiris.Deployment.Web.DADriverEditor.btnOk_Click" module="&lt;unknown&gt;" process="&lt;unknown&gt;" pid="3376" thread="47" tickCount="4636552"><![CDATA[BootWiz Argument:-driver -add -os winpe -x86 "\\myserver\NSCap\bin\Win32\X86\Deployment\temp\Drivers"]]></event>
<event date="12/03/2013 08:32:38.1506452 -07:00" severity="1" hostName="myserver" source="Altiris.Deployment.Web.DADriverEditor.btnOk_Click" module="&lt;unknown&gt;" process="&lt;unknown&gt;" pid="3376" thread="10" tickCount="4636677"><![CDATA[Fail To run Process ::System.Threading.ThreadAbortException: Thread was being aborted.
   at DriverDBMgrLib.updateDriverDBClass.InvokeApplication(String exeFullPath, String FullCmdArg, Int32 wait, Int32& retErrorCode, String& ExtendedError)
   at Altiris.Deployment.Web.DADriverEditor.btnOk_Click(Object sender, EventArgs e)