vSphere HA Waiting for cluster election to complete Operation timed out

I have enough of re-installing ESX5i (so far this was trhe quickes way to get it working on number of separate incidents - as a side not, vSphere4 just worked fine in my environment, without THAT MUCH fluffing about)

So now I have a host which almost works (lastest upgrade to 515841), but will NOT get configured for HA

It starts fine, get to the point:

The vSphere HA availability state of this host has changed to Election

and then gives "nice" Timed out

This host can be dis/connected, pinged, has VM running on it, accesses all Datastores, yet will not do HA

I went through all KB aricle:

http://kb.vmware.com/selfservice/microsites/search.do?cmd=displayKC&docType=kc&docTypeID=DT_KB_1_1&externalId=2004429

with no resolution

Anybody has any more (useful) ideas?

Thanks

Seb