HTC has released a couple of hotfixes for the original Touch Diamond that should take are of a couple of annoying bugs. (As opposed to the bugs we like, I guess.)
The first hotfix takes care of problems a number of people were having with audio playback skipping.
The second involves the Sounds and Notifications settings, specifically that you couldn't uncheck the Repeat Reminders option. So, apply this fix, and all should be well.
Note that these are hotfixes and not a full-on ROM update. Hotfixes install just like any other program. So if you hard-reset your phone at some point, you'll need to reapply the hotfixes or risk having the problems again.