.NET controls running in Internet Explorer

Hi,
our system is running .NET controls hosted in Internet Explorer. Everything
was fine up to the moment when we started to get messages: "the publisher
could not be verified", browsing the pages having these ".NET applets"
inside. The message keeps repeating each time I enter the page, user needs
to press 'Run' on the messagebox prompting.

I went to lower the security setting for the browser and dotnet:
- adding the site to trusted sites
- enabling all dotnet/activex/java downloading/executing
- making checks in registry (e.g.
HKEY_CURRENT_USER\Software\Microsoft\Internet Explorer\Download)
- i tried to sign controls giving them a strong name - no change

I'm running Windows XP professional version 2002 Service Pack 2. This is the
only version facing this problem (maybe this 'version 2002' causes this). On
other machines I'm using SP2 for XP pro for a year without any problems.

Our .NET controls of course do not have any certificate (they're not
approved by any VeriSign like agency)
- system i working in LAN only!
- we would like to avoid unneeded costs
- would this surely help anyway?
- could thi sthing be solved using test certificate (using cert2spc.exe?)


Any clue? Anybody facing this problem?

Igor Kramaric, dev.engineer

P.S. I found many articles addressing the security issues ragrding SP2 on
XP, none of them is focusing on .net controls in IE