You can learn a lot from the post #4
The whole point of using the right partitioning is it "will not" allow you to go astray with creation of partition.
You current partition table will not be accepted by cfdisk but fdisk would still read it and so can delete sdb3 and sdb4 for you.
After the deletion I ask you to change to cfdisk because your partition table becomes healthy by then and so cfdisk can operate on it. In it you will find between sdb7 and sdb8 there is a dead space left by your earlier deleted sdb3 & sdb4. If you create 2 logical partitions within the space you can "see" cfdisk automatically shift sdb8 down to eventually sdb10.
I was hoping you can see it yourself and understand it without me explaining it here. There is no better teacher than the box itself.
Your sdb5 to sdb7 are safe and not touched so all of them are good and Mandriva can be used for the rescue work without requiring a Live CD. As you didn't tell us how you boot them so I would suggest you to let Mandriva's Grub to take over the MBR as follow
Code:
grub-install /dev/sdb
Thereafter you can boot to Mandriva all the time when Suse, ubuntu and PCLinuxOS are unavailable. You can later edit Mandriva's Grub to boot all the systems.
If you have chosen Lilo as the boot loader then the equivalent command is
to be issued as the root user at terminal.
You can avoid the work by re-installation but equally you can learn a lot of useful Linux features in the process by following Post #4. It is your call. We wouldn't mind if you go either way. Let us know if you still have a problem.
You don't have to worry about the boot loader as that is easiest bit.