Bukkit

I'm having trouble getting size permissions to function.

I'm using PermissionEx
Backpack v1.9
Spigot 1.7 w/ 1.8 user compatibility

PEX Config Sample:
http://pastebin.com/68FA9FJu
Backpack Config:
http://pastebin.com/hZdpYhEx

A player placed into that group would have the default 6 rows in their backpack, even on a server restart.
I don't believe it to be a permissions issue as that rank has no inheritance and all other plugins permission nodes work fine.

What Backpack size should the player placed in that group have instead of the 6 row?

In the permission file there is this part:

- backpack.size.1 - -backpack.size.2 - -backpack.size.3 - -backpack.size.4 - -backpack.size.5 - -backpack.size.6

Im not really used to permission plugins (with that i mean plugins that give permission, not these that use permissions) so I dont know what the "- -" means compared to the single "-", but you have to know that if a player hase multiple backpack size permission the LARGEST will be used, so I'd guess that could be the problem (and if no backpack size is given the size from the config will be used). Please explain me how your permission plugin handles these 6 backpack permissions so that I can find out what the problem actually is. Another possible but I guess unlikely thing could be the Spigot server itself, because in the past I have experienced some bukkit plugins not working on Spigot.