1) I think web.config should use 2 space indenting to avoid making it too long a horizontal scroll to read (and also maybe break down some long entries to more lines)
2) has mixed casing in true/false (some are True/False), makes it harder to compare, you have to set ignore case but that might make you miss some other change that may be case sensitive
3) upload types list is missing ".pptx" file extension (only has ".ppt")
4) at the end I have:
<!-- CLIPFLAIR: NEWER AJAX TOOLKIT -->
</br> <runtime>
</br> <assemblyBinding xmlns="urn:schemas-microsoft-com:asm.v1">
</br> <dependentAssembly>
</br> <assemblyIdentity name="AjaxControlToolkit" publicKeyToken="28f01b0e84b6d53e" culture="neutral" />
</br> <bindingRedirect oldVersion="0.0.0.0-3.0.30930.28736" newVersion="4.1.60623.0" />
</br> </dependentAssembly>
</br> </assemblyBinding>
</br> </runtime>
thought it wouldn't be needed anymore, but I see you still have older AjaxControlToolkit dll in the bin folder?