http://www.democratandchronicle.com/apps/pbcs.dll/article?AID=/20051118/NEWS01/511180393/1002/NEWS
"The money, called an apportionment, is required from each of the local diocese's 53 congregations, but this is the first time anyone can remember the threat of a church being dissolved for not paying, said the Rev. Canon Carolyn Lumbard, a spokeswoman for the diocese."
I guess that the other times parishes did not pay did not pose a threat to the legitimacy of the hierarchy. It shows that the diocese has a real fear of the truth.
Another important fact, from the same article:
"All Saints did offer to put the money in an escrow account until 2006, when the U.S. Episcopal Church holds its next general convention, but the local diocese turned down that offer."
So it's clearly not a matter of the parish's solvency or of its willingness to pay its apportionment to a diocese that will remain a part of the Anglican Communion.