Pessimistic Locking -> Cannot edit fields

Hello,
that's my problem: I must develop a multi-user application (exactly
for 2 users), using Access 2000 as database. Then I thought to use
ADO, with the following settings:

* CursorLocation: clUseServer
* CursorType: ctKeySet
* LockType: ltPessimistic

Now, if I try to put some data-aware components onto a form (like a
dbEdit), I'm not able to edit any field, since I receive an error msg
like "Cannot update the field". This error happens yet if I try to
edit manually a table, using ADOTable1->Edit() (note: I defined a
primary key for each table, and I use as a provider Microsoft Jet
4.0).

Then my questions are:
1) Is it normal, using the previous settings, that I cannot edit any
field?
2) Are these settings correct for a multi-user scenario?

Thank you,
D.