Default HTC Home display - email number problem

Hi

My S740 on Orange has an issue:

I use "HTC Home" as my default display, all very nice until I get an email (got the send/receive set to do it every 30 mins or so).

If I get 1 email, the display on HTC Home says I have 2. If I get 2 emails, HTC Home says 4 etc

Two ways of getting the display on HTC Home set to correctly display the number of unread emails - restart the phone, or change to another "Home screen layout", and then back to HTC Home again.
Works OK... until you get another email.

Anyone else get this? Anyone else know a permanent solution?

Cheers

Craig