A bunch of "GPL#" showing up as layers in Raster Calculator

[KylePurdon]

I have been working just as I always do with the raster calculator and all the sudden every time I do something a bunch of random layers show up in the raster calculator. (See Image)

The are named:
GPL1
GPL2
GPL3
GPL4
...

These layers are not anywhere on my computer nor do they make any sense and every time I do a calculation more show up. I have no idea what they are or what they mean but they are very annoying.

Any ideas on what these are/why they are there/where they are coming from ?

Thanks!

[KatyAppleton]

I realise this thread is pretty much a year old, but I am having the same problem. Can anyone shed any light?