Network adapters, netsh and WMI problems in vista

I'm currently having difficulty using "netsh" in vista. I've recently
migrated from XP where I had no problems. The first problem is that I'm
trying to manage the ip addresses attached to various network cards, simply
by adding and deleting, I am not able to add IP addresses to the network
cards I want, instead the addresses keep getting added to the interface named
"Loopback Pseudo-Interface 1". These additions can be viewed using "netsh int
ipv4 show ipaddresses", but not using "ipconfig". I can add alternate IP
addresses to network cards via Network Connection, Properties, IPv4,
Advanced, and view them using both methods described above.

The second problem is that after a while when attempting to add an IP
address I keep getting the following error,

netsh interface ipv4>add address "Network Connection Name (i.e. Local Area
Connection 1)" 10.254.254.20 255.0.0.0
Failed to configure the DHCP service. The interface may be disconnected.
The system cannot find the file specified.

I am able to specify "Loopback Pseudo-Interface 1" as the network connection
name
with the add and delete, and I never get the error when I'm deleting IP
addresses even after the adding started to fail. The state of the interface
has not changed and the error persists if I disable and re-enable the network
card, or if I pull and then re-insert the network cable.

A third problem I have, although I do have a possible work around, is that
when attempting to discover the network settings of my PC programmatically
using WMI, the WMI database does not seem to have any knowledge of the
"Loopback Pseudo-Interface 1" interface or any of its IP addresses in the
Win32_NetworkAdapter or Win32_NetworkAdapterConfiguration instances. My work
around is using MIBII (Management Information Base) to obtain these
properties, but its undesirable.

Can anybody help me with these issues,

Thanks,

Ollie