Yes, estudio and "ec -gui" now seem to behave the same.  The first control-C
results in an Internal EiffelStudio Exception window, as expected.  A second
control-C then results in an Uncaught Exception window (for either estudio or
"ec -gui").  So the behavior is consistent, but seeing an Uncaught Exception
window makes me think that something is amiss.  If this is the intended
behavior (or if it is not the intended behavior but you don't think you can
improve this any further), feel free to close this report.