steve_h,
try to do the following:
1. Quit all the instances of Parallels Desktop;
2. Remove the file ~/.parallels_settings
To accomplish this, open a terminal window and enter the command:
rm -f ~/.parallels_settings
3. Run a Parallels Desktop again. The window should be placed to its default location (at the middle of the screen).
Regards,
Serg
Parallels Development Team member