Mac Pro eSata Snow Leopard

OS X upgrades generally go extremely smoothly. You can imagine that most users will find it most convenient to upgrade rather than reformat, and Apple engineers work very hard to make sure the process is smooth. (You can rest easy that an upgrade install won't be missing anything you'd get from a clean install.) In fact, having upgraded to Snow Leopard on a few machines already, the install process is even more painless than ever before. With such a recent machine, I wouldn't foresee any problems.

It's always wise to check for compatibility of third-party software and devices — for example, my wife has a BodyBugg that depends on a kernel extension to interface with the system, and the driver hasn't been updated yet. For now, I'm keeping around a Leopard partition on the drive for the "just in case" scenario.

By the way, you can partition without formatting by using Applications → Disk Utility, and the migration assistant can transfer data between partitions. Thus, if you're paranoid, it might pay off to create a Snow Leopard partition, do a clean install there, and migrate your data from the Leopard partition. Once you know it all works, either upgrade the Leopard partition or stick with the new one, then erase and re-merge the unused partition.

That has happened to me with the Mail and Address Book icons, they became invisible but the blue dot would remain when the apps were in use. It seemed odd that it would happen with the two Apple apps.

My procedure for correcting the problem affects only the app with the problem.

• quit the app
• right click (I have a two-button mouse) on the invisible icon
• chose 'Options - Show in Finder'
• chose 'Options - Remove from Dock'
• rebooted the app from the Finder window
• chose 'Options - Keep in Dock' and moved the icon back to its original place.

That immediately corrected the problem. The icons remained after reboot.