Searching this newsgroup, I found a posting which suggested this:

QUOTE
From the SBS console, click Administrative Tools > Component Services
(or, if you prefer: click Run > comexp.msc)
* Expand down Component Services > Computers > My Computer > DCOM
Config
* Right click on IIS WAMREG Admin Service, then click Properties
* Click on the Security tab
* Click the Edit... button within the Launch and Activation
Permissions section
* Click Add and add the user named: 'Network Service'
(NB: this is the step that confuses people. Most instructions simply
tell you to add the appropriate user, but do not make it clear which
user to add!)
* Click on the checkbox to Allow (enable) the Local Activation rights
option for this user
* Click OK twice, and close Component Services
* Finally reboot the server for good measure and to ensure the change
takes effect
UNQUOTE

I've done that and the errors have gone away. My question is: have I
compromised the security of the server by doing this?

Many thanks - Anthony