Peter,
Does it work if you upload a file less than 30 MB?
Can you do the following tests?
1. Upload a 2MB file.
2. Upload a 20 Mb file
3. Upload a >30 MB file
Keep me posted
The following information may help.
IIS7 and large files
By default in IIS 7 requestFiltering has the MaxAllowedContentLength property enabled. It specifies, in bytes, the maximum length of the content in a request. The default is 30,000,000 (approximately 30 megabytes.) To change this value you must edit the following file:
%windir%\System32\inetsrv\config\applicationHost.config.
In the ApplicationHost.config file, locate the <requestLimits> node.
Modify the following code.
<requestLimits maxAllowedContentLength ="10000000" />
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