Hi,
Unfortunately, the WBFS format is very ugly and each application, loader etc
has it's own patched wbfs library, compatible or not each others.
The one used in QWBFS Manager is old and not updated.
I'm planning to move to WiiTools library when i will have time.
For now if it does not show the partition even in root user, considere QWBFS
Manager is not compatible with your current partition :/
Sorry for the inconvenient.