hi guys
I manage to make my company's OWA email address on my Blackberry Javelin.
However i have following problem
it seems that messages are arriving to my Blackberry inbox 15minutes later than received on OWA.
it is always 15minutes exactly because i have been timing emails as they are received.

tis only happens on my work email. I have 4 other email accounts set up and all work right

This is normal.
BIS polls OWA mailbox on a 15 minute schedule. You can't change this.

Other email accounts such as Gmail and Yahoo have specialized integration which offers a more real-time push.

tnx m8 for your reply

Has anyone heard of 6 / 7 hour delays in emails coming to a BB when setup with BIS & OWA?

Sure.
If BIS is down, or OWA is inaccessible, or device is out of wireless coverage. ;)

6-7 hours consistently... no. That means there's something very wrong with your setup.