VB.Net paper sizes when plotting

I am trying to create a VB.Net plot routine which will hopefully turn in to a batch plotter. Being the lazy sort I have stolen code from the net (actually I think it is the one AutoDESK supply) but I am having trouble specifying paper size as you can see from the commented code below.

[font=Consolas][size=2][color=#008000][font=Consolas][size=2][color=#008000][font=Consolas][size=2][color=#008000]'' Set the plot device to use[/color][/size][/font]
[/color][/size][/font][/color][/size][/font][font=Consolas][size=2][color=#008000][font=Consolas][size=2][color=#008000][font=Consolas][size=2][color=#008000]''acPlSetVdr.SetPlotConfigurationName(acPlSet, "DWF6 ePlot.pc3", "ANSI_A_(8.50_x_11.00_Inches)")[/color][/size][/font]
[/color][/size][/font][/color][/size][/font][font=Consolas][size=2][color=#008000][font=Consolas][size=2][color=#008000][font=Consolas][size=2][color=#008000]'acPlSetVdr.SetPlotConfigurationName(acPlSet, "EUGBHORPD026.PC3", "A3_(297_x_420_mm)")[/color][/size][/font]
[/color][/size][/font][/color][/size][/font][font=Consolas][size=2][color=#008000][font=Consolas][size=2][color=#008000][font=Consolas][size=2][color=#008000]'acPlSetVdr.SetPlotConfigurationName(acPlSet, "EUGBHORPD026.PC3", "A3 (297 x 420 mm)")[/color][/size][/font]
[/color][/size][/font][/color][/size][/font][font=Consolas][size=2][font=Consolas][size=2]acPlSetVdr.SetPlotConfigurationName(acPlSet, [/size][/font][/size][/font][font=Consolas][size=2][color=#a31515][font=Consolas][size=2][color=#a31515][font=Consolas][size=2][color=#a31515]"\\EUGBHORFILE003\EUGBHORPD006"[/color][/size][/font][/color][/size][/font][/color][/size][/font][font=Consolas][size=2][font=Consolas][size=2], [/size][/font][/size][/font][font=Consolas][size=2][color=#a31515][font=Consolas][size=2][color=#a31515][font=Consolas][size=2][color=#a31515]"A3"[/color][/size][/font][/color][/size][/font][/color][/size][/font][font=Consolas][size=2][font=Consolas][size=2])[/size][/font][/size][/font]

The DWF6 line is the original. Plotter 26 is my prefered plotter while Plotter 06 is the one I can get to accept a paper size of simply "A3".

I get the same results whether I use the full name or a .pc3 name.

Plotter 26 has the following paper sizes available to it.

I want to use A3 but the two obvious syntaxes have been used (see code) without success. Can anybody suggest a way forwards?

oh well,

curiously, plotter 026 is accepting "A3" as a paper size today. I am certain it didn't yesterday. At least the problem has gone away (for now?).