IE shouldn't break if there's a simple user reference to a global entity which is not there anymore. This is a clear IE bug IMO.
This whole issue is OS and storage-flavour independent. Same issue is there in OS X, or whether you use .xml, .ini, registry, whatever. There's no real uninstall-time solution to remove per user leftovers. In OS X there's no install/uninstall for the majority of apps, it's just copy/delete.
Removing the leftovers is not always preferable anyway, since user can reinstall app later on and expect the settings to be there.
So, what apps can do is to handle user-settings/data with great care, and what the OS can do is to not slowdown/crash/misbehave if there are a few settings left there. Plus both of them should make it as easy as possible to identify, delete/move/save/restore these data. Fully file based setting/data storage has an advantage here, especially if there's a clear folder layout helped/enforced by the OS.
10/5/2005 7:11:00 AM by gar