Hi Dave,
I have seen another customer who has the same issue, and trying to re-produce it here. In the mean time, if you like please try adding a delay, it should work.
Adding a delay could be done be editing the DOS template in Console. To do that,
Run Ghost Boot Wizard
Select drive mapping boot disk
Select the network template you use, and select copy
It will create a copy of the template with (2) postfix. So your original template could be keep intact.
Select that copy, and select modify
Select Advanced, and add a DOS wait program. This will add to the \Net directroy.
In Autoexec.bat window, add something like
\net\wait 15
Select this new template for the client and try the task.
If you want more details on this please let me know.
Krish