problem on grant permission to user

I have two kinds of functions in the database that need to grant exec permission to user appUser.
The first kind of function return ordinary datatype, let's call it funcReturnDataType here.
The second kind of function return table datatype, let's call it funcReturnTable
When I issued the folloing command to appUser, no problem.
grant exec on funcReturnDataType to appUser

However when I issued:
grant exec on funcReturnTable to appUser

I got the following error message:
Server: Msg 4606, Level 16, State 1, Line 1
Granted or revoked privilege EXECUTE is not compatible with object.

Any suggestions to resolve this problem?

Thank you!I'm having the same problem. Can anyone help.|||

Maybe this will help you:

http://msdn2.microsoft.com/en-us/library/ms188371.aspx

from the article:

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permission
Specifies a permission that can be granted on a schema-contained object. For a list of the permissions, see the Remarks section later in this topic.

ALL
Granting ALL does not grant all possible permissions. Granting ALL is equivalent to granting all ANSI-92 permissions applicable to the specified object. The meaning of ALL varies as follows:

Scalar function permissions: EXECUTE, REFERENCES.
Table-valued function permissions: DELETE, INSERT, REFERENCES, SELECT, UPDATE.
Stored procedure permissions: EXECUTE, SYNONYM, DELETE, INSERT, SELECT, UPDATE.
Table permissions: DELETE, INSERT, REFERENCES, SELECT, UPDATE.
View permissions: DELETE, INSERT, REFERENCES, SELECT, UPDATE.

....