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 )

Large file support limitations

The following features do not support files larger than 50 MB:

  • Virus checking.
  • Picture libraries.
  • Streaming files.
  • Client-side restoration of smigrate backup files (limited to 2 GB). The manifest files for an smigrate backup cannot be larger than 2 GB.
  • Site templates (limit of 10 MB per site template, including content).

 

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 ...