Unique bumblebee? Or something more?

Definitely post pics of the parents and clutch if you can find them. My guess would be some type of reduce pattern third gene (especially if some of the other clutch mates have a similar look to them).

Thanks again everyone for you responses.

Here are some images I managed to find which may help, I apologize as some are not the best.

Sire (Pastel) of the clutch as a baby:

http://i.imgur.com/GZJRq.png

Another picture of the Sire (Pastel) of the clutch:
http://i.imgur.com/rU6ca.jpg
Dam (Spider) of the clutch:
http://i.imgur.com/DomHH.jpg?1

Dam (Spider) again:
http://i.imgur.com/ShlEW.jpg?1

Clutch inside of the eggs - 1 Bumblebee, 1 Spider, 3 Normals:
http://i.imgur.com/XPqB5.jpg
Male Spider from the clutch:
http://i.imgur.com/sryqD.jpg

So if anyone else has anymore further takes on what could be happening here, please feel free to share, it'd be much appreciated.

Thanks again, Dean