Can't maintain calls

[thesumo]

So, I've had my Droid for about a month, and so far have loved it. Today, however, I began having trouble making calls. I can call, and use speakerphone, but if the swcreen turns off (for example, if I put the phone to my ear) I lose signal entirley (no matter how good it was before) and the phone often will not quit the now black with call buttons screen. I've been having slowness issues in general, but this is the first bona fide glitch. Help!