During a upgrade from 5.5 I was called in to take a look why DRS acted strange on one of the hosts. What I found was above mentioned differences in the host configs. Could these values be relevant? The numbers above are from the failing host. Other hosts had both higher and lower numbers than this. Not much can be found regarding resourcegroups in esx.conf at our friend Google.
There is a resource pool and also VM's with reservations.
After resetting the reservation settings(without doing any actual changes) the problem went away and after a reboot of the host all above lines in esx.conf disappeared except for the first and the last one.