Problem creating appointments by clicking on timeslot

[Iain T]

Win XP, Outlook 2007

A colleague is having problems with creating appointments - no matter what
timeslot she double-clicks in her calendar, the new appointment window sets
itself to the next available timeslot from the current time - i.e., if at
11.50am she double-clicks on Friday 1pm, the new appointment window appears
with the time set to today at 12pm. This behaviour follows her onto other
machines.

I have been searching about on the web, but can't find an answer - any ideas?

Thanks,

Iain