I haven't seen that error message since the early days of vista, when there truly was a problem using network printers.

Not that any of these suggestions will fix your problem but things to consider...

If the printer is already connected, there really is no reason to reconnect it every time the user runs the script. One option is to use the PrinterConnection udf and check for the printer before adding it. PrinterConnection can do other useful things as well. You can also use Primapstate udf to check for network printers.

Curious what your $IPPrinters variable contains.

Some of your lines of code would benefit by putting $RC= in front of the functions so that it silences all those 0s and 1s from displaying during the execution of the script. For example... $RC=addprinterconnection(...) and $RC=redirectoutput(...)

PrinterConnection -
http://www.kixtart.org/forums/ubbthreads.php?ubb=showflat&Number=203840#Post203840

How to use UDFs -
http://www.kixtart.org/forums/ubbthreads.php?ubb=showflat&Number=81943#Post81943

The rest of the UDFs are here -
http://www.kixtart.org/forums/ubbthreads.php?ubb=postlist&Board=7&page=1