Has anything been found related to this issue? It has plagued me since version 7 (and I am now using 9).
What I have seen is the following: After clicking Import, the cursor turns into a spinning circle (Windows 7/64-bit), and the number of imported records increments in the status bar. After a few hundred (or thousand) records are processed, the incrementing record count stops, and PL/SQL Developer goes into the "(Not Responding)" state. The records will continue to be imported even when PL/SQL Developer is not responding. In my cases, eventually it does complete the import (if it is left running long enough).
I'm guessing that MS Windows is noticing that PSD is not responding to events, and is assuming that the app is hung. When in this state, it is not processing the window updates, and the incrementing counter appears to freeze.
When doing an import, is there *supposed* to be any keyboard interaction allowed? For example, can someone change windows and do editing while another window is importing, or is PSD supposed to be 'hung' while an import is occurring?