Okay, this is probably my #1 complaint with an iPhone. (and before anti-mac folks flame me - I am still keeping the phone, it is still worth it inspite of this bug).

The way an iPhone works with Gmail POP3 is, it downloads the headers first, and then downloads the messages. Then, if you are offline (i.e. no coverage or wifi: rare circumstance), it shows the cached version. Otherwise, it re-downloads the message from gmail whenever you view the message. This is great, except, it confuses the crap out of gmail, and you frequently get "This message has not been downloaded".

WTF.

Here is a solution that makes it tolerable (but still not perfect):

• Open another gmail account. say, second@gmail.com
• Go to your mail account, say, first@gmail.com, and set autoforwarding to every message to second@gmail.com
• Setup your pop3 mail on your iPhone using the following parameters:
• username "recent:second@gmail.com"
• delete messages: when removed from inbox
• delete from deleted items: in 1 day.
• On the gmail server for second@gmail.com, set "When messages are downloaded over POP3, delete them".
• Use different sending options: use first@gmail.com as your sending login-id.

That's about it. Using the above reduced my "message has not been downloaded" error message to about 1/10th of what it used to be.

If this still continues to annoy me, I might try an IMAP solution - But I am hoping Apple fixes this "BUG" (yeah, this is a worm in your apple).

But well, the iPhone still rocks IMO. This is a minor annoyance overall.