Merging computers

Ok I have two computers on my computer list named "Minime" which are the result of some underclocking for stability. So they are in escennce the same machine but with different processors. One has 0 credit (online for an hour maybe) the other is the current underclocked machine with lots of credit. I used to have a third "Minime" but I sucessfully merged it to one of the other minimes. I have tried to merge them together but I'm not getting the form choicebox where I chose which machine to merge to. I also tried to delete the machine with 0 credit but it said it had existing results. I would like to clear the old 0 result computer out but I don't know how I can if both Merge and Delete won't work.

Do 0 credit computers dissapear after a while? Is just my account broke? thanks.