Outlook 2007 - stops downloading emails

[Ram]

My system is – Windows Vista business / MS office 2007 sp2

I have a strange problem with outlook. I am not sure but I suspect that
this problem began after I update office to sp2

I have several email accounts with the same ISP. For example, say, I have
acct#1 and acct#2

Sometimes during the day outlook stops downloading emails. There were no
emails in outbox.
This particular time it happened while downloading from acct#2. (acct#1 had
no emails.) I got stuck at "receiving message 4 of 4 (8.9 mb of 8.93mb) " for
over 30 minutes.

I cancelled send/ receive. Then I clicked on send/receive.
- now it got stuck at "preparing to send and receive" – I left it for 30
minutes

I cancelled send / receive
Tested all email accounts. Microsoft sends out an email -

Using webmail (from my ISP), I moved all 4 emails in acct#2 to “draftâ€
folder. Thus there were no emails in acct#2

I clicked on send/receive.
- now it got stuck at "preparing to send and receive" – I left it for 30
minutes

Cancelled send/ receive and closed Outlook.

I could not start outlook again.

From task manager, I cancelled outlook (it was running there)!!!

Now it worked just fine.

This happens few times a week.

Any suggestions?
Thnaks