Recently, I downloaded openSUSE 11.2 DVD.
I read here (Partitioning/Install Guide) that GRUB may not dual boot correctly with windows:
It should be said that grub does not always get the settings to boot Windows quite correct and you may later have to adjust the /boot/grub/menu.lst file in your Linux installation
Is it true also for the openSuse version (11.2) that I downloaded? Please refer to Windows 7.
Thank you 
It is as said in the quote. It normaly does, but apparently there are situations where it doesn’t. You can repair that later and get help here for that whe needed.
It seems that Vista gives more problems in this area then Windows 7.
It’s not a real big problem, have lots of clients that dual boot. Where most of the problems occur is that Windows 7 usually is pre-installed with a small recovery manager partition that if left listed in the Grub Menu and then accessed by accident it will see grub and try to restore Windows to factory. But, if you remove the entry or otherwise block it from running accidentally, then all goes well (until you install certain updates that don’t play nice with a non-windows bootcode.