All of our sites that use FTP protos have issues with FTP threads when the remote FTP server goes offline during operation or is offline during thread startup.
I used a Tcl proc to write out an FTP script in a upoc that is then eval exec’d and got similar behaviour. What appears to happen is that the process hangs and if you then try and stop the process it panic’s.
If there is a solution to this I’d be interested to here it as well.
We wrote a TCL proc that does the same thing as the protocol drive, it was my understanding that the problems with the ftp driver was fixed in a release.