Sounds like Outlook doesn't close properly for you.
See http://www.howto-outlook.com/faq/outlookdoesntclose.htm

Signature
Robert Sparnaaij [MVP-Outlook]
Coauthor, Configuring Microsoft Outlook 2003
http://www.howto-outlook.com/
Outlook FAQ, HowTo, Downloads, Add-Ins and more
http://www.msoutlook.info/
Real World Questions, Real World Answers
-----
> when i close outlook and then attempt to switch profiles - outlook is
> opening
> straight back up again and not giving me the select profile option. I've
> checked the help pages and made sure that the prompt for a profile box is
> checked but it makes no difference. I'm having to reboot the pc to get the
> prompt option again. Help please someone?
Deano - 16 May 2008 21:31 GMT
Thanks for your help. Turns out it was Skype software which I loaded and have
now uninstalled. I'll get in touch with their technical team for advice.
> Sounds like Outlook doesn't close properly for you.
> See http://www.howto-outlook.com/faq/outlookdoesntclose.htm
[quoted text clipped - 5 lines]
> > checked but it makes no difference. I'm having to reboot the pc to get the
> > prompt option again. Help please someone?
Roady [MVP] - 17 May 2008 10:46 GMT
Yes, Skype has an option to display Outlook contacts. I have that option
turned off.

Signature
Robert Sparnaaij [MVP-Outlook]
Coauthor, Configuring Microsoft Outlook 2003
http://www.howto-outlook.com/
Outlook FAQ, HowTo, Downloads, Add-Ins and more
http://www.msoutlook.info/
Real World Questions, Real World Answers
-----
> Thanks for your help. Turns out it was Skype software which I loaded and
> have
[quoted text clipped - 12 lines]
>> > the
>> > prompt option again. Help please someone?
Mojo - 19 May 2008 00:44 GMT
Thanks much for this post! I just downloaded Skype and ran into the same
problem with switching between my Outlook profiles. I disabled the Outlook
option on Skype and all is right with the world again (or at least Outlook!)
Much appreciated!
> Yes, Skype has an option to display Outlook contacts. I have that option
> turned off.
[quoted text clipped - 15 lines]
> >> > the
> >> > prompt option again. Help please someone?
Roady [MVP] - 19 May 2008 10:20 GMT
You're welcome! :-)

Signature
Robert Sparnaaij [MVP-Outlook]
Coauthor, Configuring Microsoft Outlook 2003
http://www.howto-outlook.com/
Outlook FAQ, HowTo, Downloads, Add-Ins and more
http://www.msoutlook.info/
Real World Questions, Real World Answers
-----
> Thanks much for this post! I just downloaded Skype and ran into the same
> problem with switching between my Outlook profiles. I disabled the
[quoted text clipped - 27 lines]
>> >> > the
>> >> > prompt option again. Help please someone?