You are 100% correct, WorldTraveler. Legacy United F/A's did receive their profit sharing through a disbursement into their 401k accounts. This method for profit sharing was put out for a vote by AFA about 5 years ago, or around the time UAL was emerging from bankruptcy proceedings. At that time, the majority who voted in the special election, elected to have all future profit sharing payments go into each F/A's respective 401k account. Profit sharing would have been taxed as a bonus and subject to heftier tax liabilities so the membership voted to have such payments tax-deferred through disbursements into their respective 401k accounts.
As it relates to the situation with CO F/A's; their FY 2010 profit sharing was contingent upon the work group negotiating and then ratifying a tentative contract agreement. The TA had to be ratified by the time disbursements came due, but the F/A's did not bite. As such, they were not awarded profit sharing when checks were cut for the other CO work groups.
As both IAM and AFA are vying for the right to represent F/A's at the combined carrier, it doesn't exactly send a good message to legacy UAL F/A's that the IAM would draft contract language that made profit-sharing payments contingent upon ratification of a tentative agreement.
I can also tell you that the situation with regard to CO's F/A's has caused a significant morale problem on the CO side with echos that the new United Airlines is not Bethune's, nor Kellner's way of conducting business...