Since we do not have current versions of AutoCad, we use PowerPoint to test PaperFormats. 
Like all Office programs, PowerPoint outputs (fulfills 100% Standard Formats) upto A0. 

Unfortunately we are not AutoCad experts. But we may show you that our driver outputs correct paper sizes: 

1- Download a PPT file (A0 size) from: 

http://www.ncl.ac.uk/search/?q=landscape&within=www.ncl.ac.uk%2Flibrary%2Fservices%2Fgeneral&num=10 

2- Open it in PPT and use the Informatik Image driver as the 'printer'

3- Under properties set the paper size to A0

The output TIF must be an A0 

Also, see our FAQ: 

http://www.expert-tools.com/cgi-bin/FAQ/fom?file=25