I have a problem with Zimbra and unless I can fix it then it may be the end of Zimbra for us!

The problem is not Zimbra's fault however! Zimbra is a wonderful piece of software (apart from the lack of shared IMAP folders but that's another story).
The problem is Act 2007 (which I shall hereafter refer to as 'Sodding Act'!)

We were using Sugar as our CRM and I was looking forward to the eventual connection between Zimbra and Sugar. However, due to various problems with Sugar and under pressure from all the 'Windows loving/Linux hating' employees at my place of work I gave in and the Boss agreed to spend the £5000 on upgrading to the latest version of (Sodding) Act!

So there is no way back from this now, I must get used to Act and Sugar has gone in the bin. I just have to swallow my pride and accept defeat!

So I have embraced Act with open arms and gritted teeth.

After setting it up and letting it use my Outlook Zimbra profile as it's way of sending mail, (you have no choice in this as it won't connect to an IMAP server unless it's MS Exchange and will use no other Mail client other than Outlook), it appeared to work fine!
It sees all my Zimbra folders and mail correctly on my version of Outlook 2003 that has the Zimbra connector installed. Unfortunately it will not send mail! When I click on a Contact within Act it opens up the Act email plugin, puts the correct recipient in the To: box and I edit the message but when I click on 'send' or 'send/recieve' the mail doesn't go! It just sits in the Act email Outbox, you can't move it, edit it or delete it! If I then also open Outlook seperately after having carried out the previous steps and with the Act email still on screen, I click send/recieve in Outlook and the mail goes!
I know this is nothing to do with Zimbra at this stage but thought I'd just get it all clear.

Now this is using Act's own email program which just sit's on top of Outlook and uses Outlooks settings as it's own. You can instead direct Act to just open Outlook and use it instead of it's own mail client.
This is preferable as the Act mail client is basic to say the least!
Now using Outlook on it's own with the Zimbra with the connector I can send and receive perfectly.
However if I choose to use Outook as my Act mail client instead of Act Email (in the settings within Act) then the To: field does not get filled in and I get an error message from Outlook about the Server thowing an exception.

Basically, (I know I am staring to ramble a bit but bare with me), Act does not seem to like using the Zimbra profile, if I just make a new Outlook profile not linked to Zimbra but to our OpenXchange server as a simple IMAP account and no plugin involved it works fine! It just doesn't seem to like the 'kind' of profile that the Zimbra connector gives you.

So, finally, HELP! Having spent all that money on Act and a lot less on Zimbra it will be Zimbra that suffers if we can't fix this!
I have just done a fresh standard install of Zimbra, to see if I had messed something up before, created one user (me) and it still doesn't work.

This is Zimbra Network Edition version 4.0.3 (GA406) with CentOS 4.4 and on my workstation, Windows XP, Outlook 2003 SBE or Professional with either no service packs or with SP1 installed or SP2 installed and Act 9 (2007) running on a Windows 2003 server with SP1 and MS SQL5 installed (this is needed for Act).

I'm not sure this is really a support thing so thought I'd best ask here first.