Originally Posted by brandmarked

Try installing Audio Manager from the market to check your volume levels.

I had this problem when I first got my Tattoo and Audio Manager solved it. It allows you to see and control the alarm volume which is not that visible elsewhere. Audio Manager includes a widget that lets you see all the different volumes at a glance.

(You can actually change the alarm volume by

Clock > Alarm icon > select alarm > alarm sound > use hard volume controls to turn alarm volume up and down (it is independent of other sound settings)