Re: been there - seen that - never been shouted at to that extent (yet)
dragging items/folders into other locations and not being able to find them - check
helpdesk staff restoring most of a mailbox because the user insisted that everything was gone (just moved) - check
Oh yeah moving the entire folder containing mails from one project to another one without realising it is a classic. I had a call from someone who'd done that thinking they were moving one file. Then immediately afterwards spotted the folder was missing and called me. As they'd phoned immediately after doing it I was able to say "Press CTRL and Z" which fixed the problem. I then had to explain that this would not always work and the minute they spot something is amiss they should phone for help and stop using the pc.
users complaining that they are not able to send/receive email, because they have ignored the warnings every day for the last 3 months about the quota - check
I've had someone go on on holiday with a nearly full (but not enough to trigger warnings) mailbox and then when they came back complained that they were unable to send/recieve. I did explain the concept of a quota and that they would have to delete somethings first only to be told couldn't you make an exception?