What size is A0?

Hi there - FYI : We're new at owning an A0 printer.

We provide an A0 printing service for keen sewists... After initial steep learning curve, we've had very fews problems until we recently when we received a file that prints but won't fit onto page properly unless reduced to 91%. This files' property info indicates it is 36 x 48inches.

I've looked at quite a few Pattern Files in Acrobat, File, Properties and they consistently show most A0 Pattern sizes are 33 x 40 (something) inches.

My understanding is that standard A0 = 33.1inch x 46.8inchs (841 x 1189mm).

This 36 x 46 inch pattern file comes from a well established Pattern Designer who's probably sold 1000's of patterns so I'm a bit confused as to why this file won't print as expected? What am I missing?

Any suggestions?

Cheers

Brent