If I recall correctly, my 7089 had "Activate IR port" assigned to quick
access key #3 when I bought it. So you might try the sequence

- Power
- Wait until fully powered up (30-60 seconds)
- Press the Quickaccess key, then 3 (within 1 second)

I don't have a 7089 anymore, but the menu structure is almost identical
to the 7389 which I still have. Afaik the only differences are the
addition of the WAP browser and the ringtune composer. So, if the above
does not work, you might try this process (which works on the 7389):

- Power
- Wait until fully powered up (30-60 seconds)
- In rapid succession, press Menu 2 5 to get to the Require SIM Card
  PIN entry in Phone Setup menu.
- Press up twice, to get to Activate IR Port
- Press OK