I also wish to map printers in a XP sp1 environment.

This works;
$rc=AddPrinterConnection('\\i1print2\i1t41179')
$rc=SetDefaultPrinter('\\i1print2\i1t41179')

This fails;
$rc=AddPrinterConnection('\\i1print2\i1t41179')
$rc=SetDefaultPrinter('i1t41179')

The 4.20 manual gives this example;
If AddPrinterConnection ("\\vleerbeer\hp laserjet 4") = 0
? "Added printer connection...."
If SetDefaultPrinter ("\\vleerbeer\hp laserjet 4") = 0
? "Set default printer to HP LaserJet 4...."
Endif
Endif

But the syntax is still SETDEFAULTPRINTER("printername")

Needs to be fixed in the manual!