Also try this:

1. put the tire on with a tube and air it up. Tada! both beads seat.

2. carefully remove the tube by breaking the seal on only one side.

3. now add your sealant, sponge some really sudsy water onto the bead & rim, and have your list of cuss words ready.

4. add air with your compressor and see if it can get the one unseated bead to seat.