Last week's iOS 4.0.1 upgrade, which supposedly only fixed the signal indicator bars, seems to be having unintended side-effects, wrecking havoc with the iPhone's photo albums.
Users are seeing black blocks where their thumbnails used to be:
It doesn't seem to affect the actual photographs, which still show up in their entirety if you browse through them full-screen. The issue seems to be hitting iPhone 3G owners the hardest: while 3GS and iPhone 4 users have reported the problem fix with a simple reboot, 3G users don't seem to be so lucky.
Another issue is that the sort order for photos has changed, some folders are now sorting by date taken instead of alphabetically, while other folders don't seem to be sorting via any discernible order.
If having a more accurate signal strength bars aren't a huge priority for you, we recommend holding off on upgrading to iOS 4.0.1. More info can be found at the Apple support forums.