iPhone email issues

I've had a problem with the email app on my iPhone a couple of times in the last two weeks.

The scenario is as follows. I have an email in my in-box on my POP email account. I delete it (send it to Trash), and somewhere during that process, the email app closes down sending me to the home screen. When I go back in again, there's my email sitting there smugly in my in box again as if to say "you aren't getting rid of me that easily".

The first time I did this, I ensured all other emails in the Trash were deleted, I reset the phone but still it wouldn't be deleted. In the end I resorted to deleting my email account and re-creating it.

Then, this week it's happened again. After much googling, I've found some reports of this happening to others, and it seems to be related to emails with larg(ish) attachments, though of the only two emails sitting in my in-box at this time the biggest was 68k, so hardly a behemoth. And it's never happened before, and I know I've had bigger attachments that that sent to me since I've had the phone.

So what's going on? Is it a flaw in the iPhone OS 3.1 update? There's nowhere that suggests this is a major or common problem, or that Apple are aware of it (and therefore are unlikely to fix it with a 0.x patch.

It's bloody irritating though.