Running within workstation both Linux and Windows guests display erratic mouse behaviour, with the mouse wandering off into the header area contrary to the direction I am trying to move. Both a windows and linux guests would each be open when this happens. (one obviously hidden behind a tab)
Typically I if I have taken the mouse out of the Workstation window, then return to the window and click (say) within a browser window the mouse will flick up into the workstation menu area. This is extremely annoying and not something that happened with VMWare 9.
[EDIT] The cause appears to be the grab input 'default' setting is perhaps uninitialised. Setting it to 'default' cures the problems.