nfs mount succeeds but apps don't find the files

[Tsjoecha]

Hello,

First of all, I'm new to this mailinglist. Please forgive me if I ask
an already answered question.

I migrated last week to Cyanogenmod 10.1, which brings my nexus 7 to
the latest android release.
Today I reinstalled Busybox, to get back my nfs mounts on my device.

I'm using the following command in Terminal :
busybox mount -t nfs 192.168.10.5:/DataVolume/
dries/fotokader
/sdcard/Pictures -o nolock,rsize=8192,wsize=8192

The mount succeeds perfectly, if I go in the terminal to
/sdcard/Pictures and execute the ls command, I can see all my pics
from my nas-device.

Though, when starting apps, like EZ File Explorer, the folder seems to
be empty. Other apps don't see the files neither.

What can I do to resolve this issue?
I'm using BusyBox 1.20.2

Thanks in advance,

Dries