Error Plotting Layers

The setup is that all layers are off. This is meant to turn each layer on individually and plot it to a file, then turn it off and plot the next layer. It plots the first file fine, but throws an error on the second file (error shown below).

Any ideas why it is failing on the 2nd file?

dim i as Integer
dim L as AcadLayer

i = 0
For Each L In ThisDrawing.Layers
L.LayerOn = True
ThisDrawing.Regen acAllViewports
ThisDrawing.Plot.PlotToFile "File-" & i & ".plt"
L.LayerOn = False
i = i + 1
Next L

Run-time error '-2147467259 (80004005)':
Method 'PlotToFile' of object 'IAcadPlot' failed

 

This has to do with background plotting in 2005.

set your system variable "BACKGROUNDPLOT" to 0

or

add the following line in your .lsp file:

(setvar "BACKGROUNDPLOT" 0)