Apparently I can't operate online stores correctly...now I own two copies of Elemental!

The other day I got an expected notice that packages had arrived at the apartment office.  I stopped by to pick them up, and the girl said "oh, I think we have two."  "Two?"  "Yeah, I'll get them."  She came back with two near-identical boxes, one a bit larger than the other, both with a return address of "Stardock Systems".  Cue the sinking feeling...

So, yeah, apparently when I tried to upgrade my order to a Limited Edition, I ended up ordering a second copy of the game instead, so I have one LE and one non-LE box.  Can I sell, lend, or give the non-LE copy away?  I seem to remember reading here that the on-disk copy protection is keyed to my Impulse account, but I have some small hope that maybe that was just the limited edition?

I'd rather avoid having to return a copy to you guys, but if it's going to be a doorstop then I don't want to keep it around.

(honestly, I'm amazed the shipments even got to me -- I apparently forgot to change the address on my Impulse account when I moved last October!  Go USPS!)