Not able to create appointment/meeting outlook 2003

[cucolinwin]

Using outlook 2003, not able to create any appointments/meeting request. I double click any day in the calendar and nothing happens. Outlook is connected as I can see on the bottom right conner. I'm able to send/receive emails. What can be the cause of this? Everybody else is just fine, this is happening in one PC only. What is this? thanks