(Dow Jones) Dealing with demanding heirs comes with the territory for trust and estate advisers, but the amount of time and energy spent on them seems to be growing.

The term "trust fund baby" may be cliched, but advisors say there's some truth to its connotation of an exaggerated sense of entitlement. Even when those babies grow older, some still act like brats, believing they not only inherited money but the right to treat an advisor or a trustee like a servant. More often than ever, advisors are dealing with heirs behaving badly.

In the recent case of W.A.K., II v. Wachovia, a minor sued Wachovia Bank, and lost, over its handling of a trust created by his grandmother. His main complaint was that the bank didn't diversify stock held in the trust; his grandfather was serving as co-trustee, and both his grandfather and father had approved the holding of the stock.

The case is on appeal, according to Bowlman T. Bowles, a lawyer for W.A.K. II, on the question of whether a professional trustee has a duty to educate a co-trustee about diversifying investments. Whether or not one sides with the grandson, some advisors see it as showing an heir making unreasonable demands.

Angry heirs don't always sue, but many vent over the phone and in person. A rise in rudeness now may stem from economic hard times, with people feeling desperate about the need to draw on a trust or worried that its investments are dwindling. A trust officer at a bank is often on the front line fielding calls, but an estate attorney may also be acting as trustee.

An heir may call a series of meetings, with dialogue getting more and more heated.

In one case, an advisor got urgent requests from the parent of a child named in a trust, pressuring for disbursements that weren't warranted. The person grew frantic, saying a catastrophe would occur if they didn't get the money, according to Dana G. Fitzsimons, a partner at McGuireWoods in Richmond, Va. Eventually, the trust officer hired Fitzsimons to help him deal with the parent's demands.

Professional trustees are trained to handle hostility and usually manage to keep a cool head. Sometimes, one who keeps a stiff upper lip with a beneficiary makes the mistake of venting to another, who turns around and repeats the conversation.

"The worst thing you can ever do as a trustee is get mad," says W. Bjarne Johnson, an attorney at Church, Harris, Johnson & Williams, in Great Falls, Mont.

Instead, an advisor needs to stay calm, take a deep breath and explain the situation, sticking to the facts. Addressing the problem often makes it vanish. Given a rational explanation of why something can't happen, a troublesome person may fade away.