I am running DNN 4.0.2 on Windows Server 2003 Web Edition.

All of a sudden, I can not upload files to any of my portals via the File Manager.  It goes through the motions, even taking a reasonable amount of time to respond at just the point you would expect the file to be being uploaded, yet the file never appears in the file system (I'm trying to upload a .pdf which is set as an allowed file type). 

I've checked the file system itself and the file does not appear, so it's not just that DNN is unaware of it.  Earlier today, I gave Modify permission to ASPNET user (although Network Service already had it) and this seemed to fix my problem - I was suddenly able to upload files again!  However, an hour later the situation has reverted to the way it was - can't upload the very same file I was able to earlier and I get no error or warning.

HELP PLEASE!!!!  Any clues?

Thanks Sebastian,

Are you referring to the Disk Space setting in Site Settings / Advanced Settings / Host Settings?  This is set to zero, which I take it means it is unlimited.  There's no limit on the size of the website itself as far as I can see, and it is only 63MB in total anyway.

Having changed nothing, the portal in question is now allowing me to upload files again.  So this problem seems to be intermittent.  Anything else I can check?

Thanks again