I have been using os x for 1 year now and yesterday I broke my install but every-time I reinstall I get an HFS+ partition error. I have finally fixed it and thought I share my success.

Well, first you must know that this error occurs either because of a bad master boot record (MBR) or the partition id is not af.

To fix this, do the following:
1. Make sure that your partition id is af. You can check this by using spfdisk or diskpart.

If you partition id is af, then carry on to the rest of the steps.
2. Boot into your installation DVD (any version)
3. Open terminal from the utilities menu and type the following

CODE
fdisk -u /dev/rdisk0

NB. If OS X is on your second HD then use rdisk1 instead of rdisk0

An alternative way is to get make an MS-DOS start-up diskette and put fdisk on it, and boot from it.
In DOS, type
CODE
fdisk /MBR

I hope this helps the people who are having this problem.