As the title suggests, I've hit a bit of a bump with Refracta Snaphot.

From the Refracta log: File iso live filesystem.squashfs is larger than 4GiB-1.
-allow-limited-size was not specified. There is no way do represent this file size. Aborting.
This problem occurred soon after my one and only snapshot success from my original Debian installation.
With only regular upgrades and a Exaile-Banshee swap out applied, the squashfs size has barely changed
from its approx 2.6GB (Gparted puts overall install disk usage at 14.73GiB out of 59.37GiB).
I decided to install my only snapshot to replace the original system. This went very well over all, with only minor operational niggles. Sadly though, the same problem occurred again...
In addition to running Bleachbit I decided to remove FPS 'Nexuiz' from the re-installed snapshot. This was a good 850MB (IIRC) reduction to the installed system. Again, same problem.
I then went crazy and removed all of 'X' and with it a huge swathe of applications and re-ran Refracta Snapshot from the CLI. Again, same issue reported in Refracta log. Very strange and not expected.

Snapshot appears to 'chug away' fine, until concluding the squashfs and creating the ISO.
I did a test 'save work=yes' attempt, which did leave me with the copied OS but nothing else except a 0 byte MD5 file..
Extra Tweaks
To avoid missing fstab errors I removed entries to leave it blank then commented out fstab in the excludes list. I also added to the excludes list: etc var alsa* to avoid 'alsactl store' errors on the live USB ISO. This worked nicely on different machines at work, detecting hardware well and booting to fully functional desktop.
This is so close to success, if I could nail the 'snapshot of a snapshot' issue. Any ideas?
Thanks