no sql-select after sql-update?

user1 does the following:
1) setTransactionIsolation(4) (repeatable read)
2) setAutoCommit(false)
3) execute 'select' statement to retrieve list
4) execute 'select' statement to retrieve 1 record
5) execute 'update' statement to lock record (dummy update)

user2 does the following:
1) setTransactionIsolation(4) (repeatable read)
2) setAutoCommit(false)
3) execute 'select' statement to retrieve same list
this statement give an exception (lock)

Both user have their own connection/transaction.  I want user 1 to lock the
record for update but user2 should be able to read them...
I understood that TransactionIsolation(4) locks a record when update/delete
without commit()/rollback().  Now it seems that records are lock for
reading also?