When using the Append, Delete Rows, and Delete Features geoprocessing tools against versioned datasets, one of the following error messages is returned:
"This operation may not be completed on versioned data"
"The object could not be edited in the current editing mode"
"This operation is not allowed while editing"
This is a known issue with versions 9.3 and 9.3.1 that has been addressed with the software patch or service pack mentioned below.