Thank you for your reply.
I have tried to select no database and then the valid connection again, but to no avail.
I have already tried to uninstall and reinstall eCart twice.
The OS is Windows XP SP 3.
The DW version is DW CS3 Version 9.0 Build 3481.
The eCart version is 5.0.6
The only other extension installed is DataBridge version 1.1.0.