No matter what I've tried, I cannot get progress messages from a python script tool to fire any of the IGeoProcessorEvents3 "onProgress" handlers. Is that even possible I wonder? The progress bar does show up if I run the tool in the foreground from ArcCatalog, which proves the python tool is issuing progress notifications. But progress events don't fire when I run the toolbox tool via Geoprocessor.execute(tool, parms). Other handlers fire - preToolExecute, onProcessMessages, and postToolExecute - but nothing for onProgressMessage or onProgressPercentage. Any ideas? (ArcGIS 10.0)