Multiple Probs: Insufficient Resources, FS Check, etc.

After 2 years of flawless service, my ReadNAS NV+ with 1Gb RAma dn X-RAID 3x2Tb disks + 2 x 2Tb USB disks (for Backup of the NAS) have started to give me a problem

When accessing the NAS from my Win7x64 machine I got the error "insufficient system resources exist to complete the requested service" and when using my XBMC machine I get the error "Invalid Argument" when connecting to the NAS.

First I did the Microsoft solution and rebooted the NAS and checked the FileSystem when Booting. That made not difference.

So I logged in thru SSH and "top" is not showing anything unusual. Nothing is using a lot of CPU or Memory, I don't have a lot of connections to the box (netstat -an), I can access all of the FS and both external USB drives, thru SSH. So I assume the Filesystem and rest of the NAS is working as it should.

Then I stopped AFP, NFS, CIFS and the FTP services and started the services one by one and tested them then one by one.
- FTP works or all users but the admin user.
- NFS does not work
- AFS does not work
- The problem is still there with CIFS.

I also have a problem downloadning the Logs so I can't provide that yet. When I can I will ...

Model: ReadyNAS NV+ [X-RAID]
Firmware: RAIDiator 4.1.8 [1.00a043]
Memory: 1024 MB [2.5-3-3-7]
Volume C: Online, X-RAID, 3 disks, 77% of 3701 GB used

Any ideas?