10.6.5

Yay! I can now access my Seagate Expansion drive using Windows and Mac OSX using exFAT. exFAT is supported in Mac OSX 10.6.5.

However, after the software update outlined in this page: http://support.apple.com/kb/HT4250, the boot-up time of my MacBook increased to more than two-folds (more than a minute). Luckily Pael pointed me to the "Repair Disk Permission" step which I think fixed the problem. Just go to Disk Utility -> Select the drive -> Click on "Repair Disk Permission". And I think it fixes the problem. The machine is now booting up in less than 30 seconds I think...