Why is samba unable to access a folder once something is mounted to it?

Edit: IT WAS F#$CKING SELINUX. echo 0 >/selinux/enforce and it works.

Edit: Based on the fact I can't view files in the directory even when they are recursively set to ugo+rwx (see edits at bottom of this post), I suspect the problem is more fundamental than the mounted share.

I have the following share setup in my samba configuration:

[test]
path = /mnt/
guest ok = yes
writeable = yes
browseable = yes

The /mnt folder has permissions as follows:

[root@[host-redacted] mnt]# ls -al /mnt
total 16
drwxr-xr-x.  4 root root 4096 Mar  3 00:54 .
dr-xr-xr-x. 25 root root 4096 Feb 25 19:04 ..
drwxr-xr-x.  2 root root 4096 Feb 26 21:45 files
drwxr-xr-x.  2 root root 4096 Mar  3 00:54 tmp

At this point, nothing is mounted to these folders. When I try to access this via samba it works fine:

[root@[host-redacted] mnt]# smbclient -Uguest //[host-redacted]/test
Enter guest's password:
Domain=[WORKGROUP] OS=[Unix] Server=[Samba 3.5.10-125.el6]
smb: \> ls
  .                                   D        0  Sun Mar  3 00:54:52 2013
  ..                                 DR        0  Mon Feb 25 19:04:02 2013
  tmp                                 D        0  Sun Mar  3 00:54:52 2013
  files                               D        0  Tue Feb 26 21:45:55 2013

                50396 blocks of size 1048576. 46487 blocks available
smb: \> cd files
smb: \files\> ls
  .                                   D        0  Tue Feb 26 21:45:55 2013
  ..                                  D        0  Sun Mar  3 00:54:52 2013

                50396 blocks of size 1048576. 46487 blocks available

However after I mount an encrypted share to that drive things to awry. I mount it and check permissions and ownership are identical:

[root@[host-redacted] mnt]# mount /dev/mapper/[encrypted-partition-redacted] files

[root@[host-redacted] mnt]# ls -al /mnt/
total 16
drwxr-xr-x.  4 root root 4096 Mar  3 00:54 .
dr-xr-xr-x. 25 root root 4096 Feb 25 19:04 ..
drwxr-xr-x. 13 root root 4096 Jul  6  2012 files
drwxr-xr-x.  2 root root 4096 Mar  3 00:54 tmp

But now when I access the share, the files directory has disappeared:

[root@[host-redacted] ~]# smbclient -Uguest //[host-redacted]/test
Enter guest's password:
Domain=[WORKGROUP] OS=[Unix] Server=[Samba 3.5.10-125.el6]
smb: \> ls
  .                                   D        0  Sun Mar  3 00:54:52 2013
  ..                                 DR        0  Mon Feb 25 19:04:02 2013
  tmp                                 D        0  Sun Mar  3 00:54:52 2013

                50396 blocks of size 1048576. 46487 blocks available

I did a quick check to make sure my guest user (nobody) can read /mnt and it seems okay:

[root@[host-redacted] mnt]# sudo -u nobody ls /mnt
files  tmp

Can someone explain what is going on? My samba configuration was copied from a previous machine running samba 3.3 in much the same setup, and this new setup is running the same configuration (files copied) but with samba 3.5.10-125.el6.

I've also checked the changelog and can't see anything that stands out.

edit: I do not have any veto files directive in my smb.conf:

[root@pmfs mnt]# grep -i veto /etc/samba/smb.conf

edit2: When the directory is not mounted I am able to cd into files - HOWEVER I am not able to see a file I created there

[root@pmfs samba]# echo asdf > /mnt/files/test.txt

[root@pmfs files]# chmod -R ugo+rwx /mnt/files/

[root@pmfs ~]# smbclient -Uguest //pmfs/test
Enter guest's password:
Domain=[WORKGROUP] OS=[Unix] Server=[Samba 3.5.10-125.el6]
smb: \> ls
  .                                   D        0  Sun Mar  3 00:54:52 2013
  ..                                 DR        0  Mon Feb 25 19:04:02 2013
  tmp                                 D        0  Sun Mar  3 00:54:52 2013
  files                               D        0  Mon Mar  4 20:05:45 2013

                50396 blocks of size 1048576. 46486 blocks available
smb: \> cd files
smb: \files\> ls
  .                                   D        0  Mon Mar  4 20:05:45 2013
  ..                                  D        0  Sun Mar  3 00:54:52 2013

                50396 blocks of size 1048576. 46486 blocks available

As well as a solution to this specific problem I'd be interested in knowing if there is anything else I should be doing to troubleshoot this problem - as I have often struggled with configuring samba I'm always interested in learning how to better improve the troubleshooting process