The right question...
Indeed, where is the space for openSUSE 11.2 in relation to Win 7?
You should use, or should have used, the Win 7 disk tool to shrink the last partition to make room for 11.2. Then 11.2 should find the unallocated space and make a reasonable proposal for installation, one that you can change as you wish.
I assume that the three Win 7 partitions are registered as primary partitions, and that 11.2 or you would format the newly created space as an extended partition, with three logical partitions for swap, /, and /home. I believe that 11.2 will put the boot loader at the beginning of the logical partition to chainload Win 7.
If you download and burn a live-cd partitioner such as PartedMagic or GPartedLive, you can use the command "fdisk -l" to check the partition table for orienteering.
The 11.2 installation DVD rather than the CD will give you the chance to make or change any partitioning scheme as is needed, and it gives you more information and control over the installation.
If you haven't changed Win 7 using the Win 7 tool, Win 7 may not boot and you will have to restore the Win 7 boot loader. This may help. Notice the link to a Recovery Disk Download.
If by chance fixing the Win 7 bootloader causes a problem with GRUB, boot the 11.2 DVD and look for the Repair option when you come that far into the process.