[mythtv-users] OT: Linux problem

[Damian]

Hi Everyone,

I have tried to get to the bottom of this problem on a more general 
Linux forum (ubuntuforums.org/showthread.php?t=2289024) but no one seems 
to be able to help.

I realise that this is off topic, so feel free to ignore, but you are 
the most knowledgeable group of Linux people I know, so ...

The short story:
One of my drives on my ubuntu server is behaving oddly as a mapped 
network drive. Whenever I try to connect to it (from either a windows or 
linux machine) I get an error message about memory. From windows, it 
says "Cannot connect all network drives", then if I click on it says, 
"An error has occurred while reconnecting S: to [path] Microsoft Windows 
Network: Not enough storage is available to process this command. This 
connection has not been restored." I can't remember the error from a 
Linux box, but its similar and mentions memory.

However, if I then click onto a different drive, and then back to the 
network drive, everything is fine! And it continues to be fine until the 
connected machine reboots.

This problem happens, without fail, every time a reboot one of the 
machines that connects to the mythbuntu server (actually a desktop install).

It all worked fine before. There's plenty of space on the drive.

Any idea what's going on?

The long story:
If more info is needed ...

I have an Ubuntu machine in the garage (actually Mythbubtu) which acts 
as a server for the house.

I have other Mythbuntu computers and Windows machines that connect to 
this machine.

A couple of weeks ago, I tried to update Mythbuntu on the server (first 
to 14.10, then to 15.04). Unfortunately, the update from 14.10 to 15.04 
didn't work (some problem with MySQL that I need to come back to). 
Luckily, I had made a ClonZilla back up of the OS at each stage, so it 
was easy to roll back to the last fully working system.

Everything seems to be working perfectly in the current 14.10 system, 
except for mapped drives from my windows machines.

I have drives S: and T: mapped to the Ubuntu server on all of my windows 
machines.

The T: drive is still working fine on all of them.
The S: drive is acting the way that I described in the 'short story' 
description above.

This is exactly the same on all of the windows machines, so I'm sure 
it's something on the server that's not as it was.

Any ideas what can be going on?
It all works eventually. It's just annoying to have to click past error 
messages on every reboot.

Thanks,
Damian

PS I'm pretty inexperienced with the terminal, so if you need to see any 
logs or output from commands, please tell me what I need to be typing or 
where I need to be looking.

How can I get to the bottom of this?