Don't know exactly, but I can speculate.
First, what do you mean, by these:
- VMware workstation (part of the workstation Pro product) (perhaps you mean that you use VMware Workstation Player?, need to be sure, because your software does not behave correctly)
- what does this mean "it appears to "spread" to other windows guest machines and then... "
- you are saying that you use "guests", but report on "guest". So, is this VM-specific, if so, what is the difference between them?
As for the speculative reasons:
- I would install VMware Player, VMware Tools against and check Ubuntu Updates
- if none of that helps, I would try to change the graphics driver or if possible graphics adapter. Change of the driver, open or closed driver, is something that you would need to figure out at Ubuntu Forum. Sometimes, wrong closed drivers may be automatically selected by *buntu-systems and taking the correct one, might be rather easy (in software sources menu, reboot required after change, you could try with open driver)
- what happens if you ran different VMs on different desktops? Then they should not interfere in any way (well, they shouldn't anyway, but worth a try?)
