What I believe to be the bug occurs when using the pGetDefPrtInf command before using the pGetPrtInfo command. Review the following code and comments (which was whipped up for demonstration):

; Initialize extender and get printer list
AddExtender("WWPRT34i.DLL")
printers = pGetPrtList(0)

; Offer list to user -- choose a local printer
chosen = AskItemList("Printers", printers, @tab, @sorted, @single)

; Display the server name.
; If you chose a local printer, the message box should be blank
srvname = pGetPrtInfo(chosen, 1)
Message ("Before",srvname)

; Now grab the default printer info
defprt = pGetDefPrtInf(1)

; Excute the same command as above.
; This time, the server name will be populated -- this is the bug.
srvname = pGetPrtInfo(chosen, 1)
Message ("After",srvname)

Exit 

Debug output is as follows:

************************************************************

*** Debug Initialized ***

==============================
Wed 6/23/2004 4:29:15 PM
WinBatch 32 2004A
WIL DLL 4.4add
\\hscinstall\scripts\code\msm Packages\PrinterInv\temp.exe
Windows platform: NT, version: 5.0, build: 2195 (Service Pack 4)
==============================

----- Extender loaded: \\hscinstall\scripts\code\msm Packages\PrinterInv\WWPRT34i.DLL (file version: 39004,0,0,0)

AddExtender("WWPRT34i.DLL")
(60) VALUE=> 1

printers = pGetPrtList(0)
(70) VALUE=> "Microsoft Office Document Image Writer HP LaserJet 5 Acrobat PDFWriter Acrobat Distiller \\hscsprint1\STHMT03 \\hscsprint3\STHMT11 \\hscsprint3\STHMT13"

chosen = AskItemList("Printers", printers, @tab, @sorted, @single)
(5658) VALUE=> "HP LaserJet 5"

srvname = pGetPrtInfo(chosen, 1)
(5668) VALUE=> ""

Message ("Before",srvname)
(8152) VALUE=> 1

defprt = pGetDefPrtInf(1)
(8152) VALUE=> "HP LaserJet 5"

srvname = pGetPrtInfo(chosen, 1)
(8162) VALUE=> "HP LaserJet 5"

Message ("After",srvname)
(9634) VALUE=> 1

Exit
(9634) VALUE=> 0

--- Normal termination ---

;;;END OF JOB;;;