TAP interface doesn't recieve IP-address

[GroundX]

I have a wierd problem on some clients connecting to the OVPN-server on pfSense box.
9/10 clients work perfectly, but 1/10 doesn't get an IP address on the TAP-adapter. So this is for sure a client side problem.

OVPN sees the TAP-adapter and gives it a IP address, but not a single packet is recieved on the TAP interface nor does it catch the IP address. The GUID is correct.
The routing table is fine, and the only "good stuff" in the log is this:
"Warning: route gateway is not reachable on any active network adapters: <ip-address>"

I've cheked permissions as far as I can, also reinstalled the client a couple of times (yes, as admin), but no luck. Disabled UAC and FW just in case.

OS is W7Px64SP1 on all clients.

Anyone have an idea of what's going on here?</ip-address>

[GroundX]

OK, update on this. Applied all windows updates (there were about 80) and now it seems to work.
Would be good/interessting to know wich KB that did solve this (if any? magical things have happened before).
Will try on another client when possible.