Hi Andreas - I am facing a very similar issue to this when upgrading from ERP EHP5 to EHP7.
We recently moved some of our processes to an HA cluster that uses a virtual IP.
We do not specify SAPLOCALHOST or SAPLOCALHOSTFULL in our START profiles. Did you have to add these parameters? SAPGLOBALHOST is in our DEFAULT profile and it currently uses the virtual IP name. Did you change the value from a virtual address to a physical server name? Also - which operating system were you using at the time?
Thanks and Best Regards - Jeff