Ran into this a couple of days ago and I thought I'd share the knowledge , just in case you are seeing this behavior:
According to http://technet.microsoft.com/en-us/library/cc262061(office.12).aspx, the value that can be set for this value is between 5 Mb Default and 2Gb. This, means anything between (including ) 5,242,880 - 2,147,483,648.
Default value is set to 5Mb and all should be well, except if you want to implement the recommendations in Configuring Large File Support .
Issues to be aware:
1. If you try to set the value to the maximum 2Gb (2,147,483,648) you will receive the following error: Value was either too large or too small for an Int32. This is because, incidentally (or not), the value represents exactly Int32.MaxValue+1 (http://msdn.microsoft.com/en-us/library/system.int32.maxvalue.aspx)
2. If you set the value to 2,147,483,647 the operation will complete successfuly BUT:
on saving any site as template you will receive the following error : Exception occurred. (Exception from HRESULT: 0x80020009 (DISP_E_EXCEPTION)) This , because a small line that might go unobserved:
(Configuring Large File Support )
The following features do not support files larger than 50 MB:
The answer to the puzzle: use 2,147,483,646 (or any other number between 5,242,880 and Maxint-2) and you should be good.
P.S. Did not test the Viruschecking , streaming, etc ...