After seeing Brascoe's post regarding removing MS updates 818529 & 811493, I decided to do some testing.
Firstly I found that my laptop, which has problems connecting via VPN the first time, did not have either patch installed.
So I proceeded to install all outstanding critical updates via Windows Update page. The following updates were applied:
818259, June 2003, IE6 SP1 Cumulative Patch
Q811114, Security Update Win XP
811493, Security Update Win XP
Q815021, Security Update Win XP
817787, Security Update Win Media Player Win XP
I then carried out some tests establishing VPN connections to a remote SME server and on every occassion the connection established first time. Prior to applying all of the above patches, I could not connect on the first attempt and I had to wait 10 minutes for SME to time out before getting a successful connection on the second attempt.
Now it was time to break it and see which particular patch fixed it. I found that if I removed patch 811493 the problem returned. I reinstalled 811493 and the problem disappeared.
Upon searching the Microsoft Knowledge base I found that MS released an updated patch for article 811493 on May 28, 2003. I suspect this is why Brascoe's version is still broken and the latest version I installed today actually fixes my problem.
See
http://support.microsoft.com/default.aspx?scid=kb;EN-US;811493 In my case at least, it appears the VPN issues of V5.6 have been a combination of SME and MS, Mitel fixed their part with Update 4 and MS with 811493 May 28 release. This may explain the differing results people have been having with V5.6.
I hope the above info is of use to people and would be interested to hear feedback from others.
Martin