Edit:
Looks like we posted at the same time. so let me revise my post.
Couple questions....
It looks like you don't have AEP (everything pack) so that explains the DVR fee (which is for the 942 BTW, the 508 has no dvr fee)
As for the receiver fees, maybe you have the 942 as the primary and are paying a lease fee and the other receiver fee is for the 508. I however do not lease any of my receivers so I don't know how they list them, I would expect to see something with the word lease in there though. Someone here will surely know.
I am assuming you have the 942 plugged into a phone line.
REVISION:
Is there a line about lease fee on your bill? If not, that second Additional receiver fee is the lease fee. If there is a line about a lease, and you have your phone line plugged into the 942 and made sure it has dialed dish at least once, then call and get it straightened out.
If you don't have a phone line plugged in and made sure it has connected once to update the records, then that second fee is the no phone line connected fee.