From this post, it seems that only very specific conditions seem to trigger this bug. Also, AFAIK, this only seems to affect the default Messaging app, using a replacement like Handcent seems to be the way to go. More info on the bug here.
Specifically, there is something about
certain email-to-SMS messages that
corrupts Android's SQLite database,
causing unpredictable results
thereafter. The most commonly cited
offender is alerts sent by Bank of
America, though SMS alerts sent by
LinkedIn and T-Mobile are also cited.
It's possible that any SMS where the
sender is an email address will do the
trick, or it's possible there's
something else these specific senders'
messages have in common.
To be clear: if you've never received
one of these corrupting messages, you
will never be able to reproduce the
bug. That's why it's only affecting a
small group of Android users.
If you have fallen prey to the issue,
you should be able to fix it by
performing a hard reset (wiping all
data) and then blocking the offending
sender(s) from sending you texts in