VMWare and time syncronization

I have an Ubuntu server with vmware-server running three other linux guests and, except, for time syncronization it runs quite smooth.
Today I eventually found some time to devote to this long-standing issue and I have applied this solution. It should keep behind the time in the guests so that the vmware-tools can update it.
On my machine I have a 3.2Ghz Pentium 4 cpu so I have set
host.cpukHz="3202000"
a bit higher to compensate for the higher frequency. Let's see how it works...

UPDATE: after two days the guests are still two hours ahead, so I decided to go for the easy route and set up a cronjob every two hours.

UPDATE 2: since time is not handled correctly also the cron job approach does not work.