System crashes when adding new partition to external hard drive
Now, using the partition tab in Disk Utility I try to add a new partition. I select a size for this partition that is considerably less than the space being taken up by time machine backups. I also switch time machine off. After clicking apply, disk utility seems to be working away for 10-20 minutes and then my system suddenly crashes. Everything freezes and the following message appears:
"You need to restart your computer. Hold down the power button for several seconds or press the restart button".
After restarting my system I go to Disk Utility First Aid tab and run 'verify and repair' on the external hard drive. This seemingly results in detection of errors and successful repair of the hard drive. Here are the details from Disk Utility First Aid:
Verify and Repair volume “Time Machine Backups”
Checking Journaled HFS Plus volume.
Detected a case-sensitive catalog.
Checking Extents Overflow file.
Checking Catalog file.
Incorrect block count for file live.1.indexPositions
(It should be 131072 instead of 65536)
Checking multi-linked files.
Checking Catalog hierarchy.
Checking Extended Attributes file.
Checking multi-linked directories.
Checking volume bitmap.
Checking volume information.
Invalid volume free block count
(It should be 105720319 instead of 61123071)
Repairing volume.
Rechecking volume.
Checking Journaled HFS Plus volume.
Detected a case-sensitive catalog.
Checking Extents Overflow file.
Checking Catalog file.
Checking multi-linked files.
Checking Catalog hierarchy.
Checking Extended Attributes file.
Checking multi-linked directories.
Checking volume bitmap.
Checking volume information.
The volume Time Machine Backups was repaired successfully.
However if I subsequently try to add a new partition, I end up with another system crash. I have been through this cycle 3 times now. Suggestions on how to resolve this would be greatly appreciated. I am open to completely erasing the drive and starting from fresh if this is the only safe solution (this drive will hold my system backups so I need it to be confident it is working properly), but I would like to avoid this if possible as it would leave me in a vulnerable position without system backup for a while.
Macbook, Mac OS X (10.5.6)