permission issue

Recently I saw that there are many changes regarding stored procedures and
I like all of them, but I have a problem with permission issue.
If I grant execution right on function to some user or group PostgreSQL
is unable
to execute this function unless it has all the necessary rights (select,
insert,...)
on all of the objects it (function) uses.
I find this behaviour of PostgreSQL strange. Seems to me that running
function under owners rights is the way to go.

If database administrator whish to grant minimum permissions possible
he certanly doesn't want to grant all the permisions required by the
function
to each group that can execute that function.

What is your opinion on this and how would you solve the problem
of granting rights to users?

Best regards,
Rikard