Same thing for me - I get calls all day from this number with either no msg or when I pick up there is no one there. It is starting to get very annoying.
Have been getting them also in the Seattle area (206 is the local Seattle area code) over the last couple of days. No message, so I ignore them. Too many telemarketers are working from their home phones - but if they don't leave a message then it must not be that important.