Quality Manager 4.0.5 not able to execute test cases after upgrade from 4.0.3

 Some (not all) test cases we can no longer execute.  Running a test case on its own (outside of a suite) presents the dialog to prompt which Test Case Execution record you want the result to live in, however it never presents any option to create a new or select an existing execution record - it simply says "loading", forever.  If I remove all existing test case execution records, and try to run it again, it works.  I tried restoring each individual execution record one by one to see if it was just one of them that was causing this issue, but each one caused the "loading forever" failure.  If I execute the test case in the context of a suite, it will not execute the manual script associated to the case, it will simply create an empty execution result record.  Any ideas how I can work around this?  If I copy the test case it is the same as removing the existing results and works ok.  I'm thinking of copying all test cases that exhibit this problem and updating all suites to use the new test cases - but that's really time consuming and hoping for a better solution from the forum...