First off you have a Wicked
Custom Skin nice work !!!
I could not find the Gallery perhaps you have it hidden

somewhere in the skin!
1) Dragonbyte-Tech: Gallery - General Options --> Gallery URL Path:
I removed URL
This can be blank if run from inside your forum directory
...which it appears you are according to the Dragonbyte-Tech: Gallery - Image Options
because the Image Upload Path is set to the default.
2)
Filename: was blank I have updated
3)
Instance Management
instance 2 & 3 were set but instance 1 was left blank
I have updated
instanceid: 1
Max Thumb Width
Max Thumb Height
Max Image Width
Max Image Height
All Instance are the same now
I was going to check something with the categories but it would have been better had I seen the link(s) to the Gallery.
Test it out and if it doesn't work I can go back in but let me know where the Gallery is located.
Cheers