Users and one iPhone Atlas staffer are reporting problems with the iPod touch while upgrading apps in iTunes 8. See this Apple discussion.

We’ve discovered this workaround: update the apps from the iPod Touch itself and then sync your iPod Touch with iTunes 8. ITunes 8 transfers the purchases to the iTunes library on your computer [...]

A number of users are experiencing problems with syncing after the 2.1 update, receiving the message:

“The iPod cannot be updated. An unknown error has occurred (13213).”

This issue can be resolved, in some cases, via the following process:

Disconnect the iPod and turn it off
Quit and relaunch iTunes 8
Reconnect the iPod (do not turn it on [...]

iTunes 8 includes some significant enhancements for iPhone and iPod Touch owners, but the improvements depend on your device’s OS version. Unfortunately, a number of users are experiencing difficulty applying the iPod touch v2.1 update, which is required for some iTunes 8-related improvements.

In our hands-on testing we found the following, OS-specific enhancements and issues:

For the [...]

There’s no such thing as a panacea for issues, including slow backups, application crashes, endless reboot and restore loops, inordinately poor performance and more, brought about by the iPhone OS 2.0 update. However, several users have found that the following is remarkably effective:

Restore the iPhone but do not restore from a backup. Instead, set the [...]

Several iPhone 3G users have reported an issue in which their own numbers are not displayed on the devices. Generally, the subscriber’s own number is displayed at the top of the contacts list (above the search function). The simple answer to this issue: the number was never properly saved to the iPhone’s SIM card.

This problem [...]

iPhone backups through iTunes after the OS 2.0.x update are inordinately long for some users, literally taking hours in some cases.

We’ve now received reports indicating that the slow backup issue may be caused by the presence of certain applications. Specifically, several users have reported that removing the application VoiceNote results in faster backups.

Some sample reports [...]

We’ve extensively covered an issue in which in which some third-party applications crash or do not launch for many iPhone OS 2.0.x users. Previous reports indicated that the issue can be eliminated by reducing the number of applications installed on the iPhone. We also noted a separate fix that involves downgrading to an earlier version [...]

Despite software update (iPhone OS 2.0.2) purported to contain fixes for the issue and innumerable workarounds, poor iPhone 3G signal strength continues to plague many users. The most damning demonstration in the United States: many users report that cheaper AT&T phones deliver significantly better 3G signal strength in the same physical location as iPhone 3Gs. [...]

We continue to report on an issue under iPhone OS 2.x in which some third-party applications crash or do not launch, for many users. Previous reports indicated that the issue can be eliminated by reducing the number of applications installed on the iPhone. We also noted a separate fix that involves downgrading to an earlier [...]

Several users have reported an issue in which the iPhone’s Mail application suddenly fails to retrieve new messages, generally after switching from one connection method to another (e.g. WiFi to EDGE or vice versa).

As desribed by one Apple Discussions poster:

“If I switch from edge to wifi or visa versa, the phone will no longer retrieve [...]