What is flashing and when does it flash?
Is it a notification area icon, a taskbar icon, or something else?
Does it flash when you get new email, a reminder, or ...?
Do you click on anything, or does the Outlook just "bring up my Outlook" by itself?
I have Office 2010 and get a notification area popup message for new email.
I also get taskbar icon flashing alerts for reminders (appointments).
In Outlook 2010 these alerts can be configured or turned off at:
Email alerts: File > Options > Mail > Message arrival
Reminder alerts: File > Options > Advanced > Reminders
I believe Outlook 2007 should have similar alert configuration capability.