I was just chatting with Dave Hay about VMWare Workstation on Ubuntu.
After installing VMWare and running "/usr/bin/vmware-config.pl" to configure it - sometimes VMWare will not start. Typically at this stage most people run /usr/bin/vmware-config.pl again in the vain hope that it will "just start working" this time.
It can be easier than that.
Just rename the file "/etc/vmware/not_configured" to something else such as "/etc/vmware/not_configured_backup" (or just delete it).
Try starting VMWare again - it should now work. You might just have to run "vmware-config.pl" again if there really is something wrong.
If, for some apparently random reason, VMWare decides there is anything less than perfect it seem to generate this file. All you have to do is update your system and apply kernel patches to get the file to regenerate.