The IRS may very well be holding up the issue. As I said previously typically the executor does not release funds (or at least holds back a sizable cushion just in case the IRS or someone else comes knocking saying the decedent owed them money) until all these matters have been settled. Now, it is completely possible the executor is lying.
---------- Post added 2013-02-23 at 04:41 PM ----------
That is more commonly the issue. I am just saying the IRS doesn't really care whether the beneficiaries get along great or creating WW3. The IRS only cares "hey your estate was worth $50 million and so you owe us $20 million". The the executor pays the $20 million and now has $30 million to distribute. Now that there is only $30 million to distribute it is who gets that $30 million that causes the family drama. For the OP since the parties agree it just goes according the the will. When the soap operate starts its when dad says the money should be split evenly among my 3 kids but the daughter or whoever says no no I cared for them therefore I should get 20 and you guys can get 5 each. It's at this time everyone sues the crap out of each other and the fun begins.
TLDR; IRS gets their cash first and then the family gets to argue over the crumbs.