I have just completed a third clean install of Snow Leopard on my MacBook Pro, Model A1278; I think I may have found a bug in Disk Utility and would really appreciate someone confirming this for me. Leopard 10.5.8, used Disk Utility version number 11.1 (252.4), but Snow Leopard 10.6.0, now uses Disk Utility version 11.5 (298). The major, and most obvious difference is the way in which drive capacity is reported, with Snow Leopard now using Base 10 rather than Base 2. For me, this is a most welcome change, but more importantly; it is obviously an intentional change by Apple. However, there appears to be another change in Snow Leopard's version of Disk Utility which does not appear to be intentional, and it has left me scratching my head. It can be seen when selecting the partition tab, and then viewing the "Available Capacity" of any drive partition. Using 10.6.0, Disk Utility version 11.5 (298.0): An empty 8GB thumb drive showed a "Total Capacity" of 7.51GB, but an incorrect "Available Capacity" of only 2.11GB. I also checked the available capacity by clicking on the partition in the far left hand column of Disk Utility, and viewing the information at the bottom of the Disk Utility window, interestingly it showed the correct amount of available space as 7.48GB, as did the Finder using Get Info; please see the attached images. Using 10.5.8, Disk Utility version 11.1 (252.4): An empty 8GB thumb drive showed a "Total Capacity" of 7.51GB, and the correct "Available Capacity" of 7.48GB using the partition tab. I obtained the exact same results using different sized thumb drives, from various manufacturers; in each case Snow Leopard's version of Disk Utility reported drastically less available capacity than Leopard's version of Disk Utility. In addition I ran each version of Disk Utility on a blank system hard drive, booting from installation DVD's 10.5.7 and 10.6.0 to check the reported available capacity of various external hard drives and various solid state drives. Booting from the DVD's the results were the same; Snow Leopard's version of Disk Utility reported considerably less available capacity than Leopard. I have since reinstalled Snow Leopard and updated my system to 10.6.1 but the issue has not been resolved. Please could someone experiment with this and let me know what you find ? Thanks in advance.