I went thru this yesterday also. It seems that it was a new "feature" added only just yesterday, and the elite line really was no help except to pass me to the electronic support desk. They too had not dealt with it much yet, but were able to snag me the bulhead seats after about 1/2 hour on the phone.

Today I noticed that some flights have the blue bulkhead seats and some have reverted back to the occupied or blocked depiction that was prevelant post 3/17 seatmap up until yesterday.

It seems that they want to get extra revenue for them from non elites, but are required to hold a few anyhow for possible disabled pax, and just haven't yet worked the bugs out. It will be a rush at T-23:59 if they leave it as it was yesterday. Agreed it is frustrating showing as "Availble", but not being "Available".