Hi, are you sure that the accounting server was ever alive and handling accounting packets? Those logs look exactly like they would if , for example, you were sending auth+acct to an IAS RADIUS server not configured for accounting.
the RADIUS server attempts to send an accounting packet to it...doesnt get an accounting response. marks it as dead...has a timer, knows no better than presume it alive and then back to step one. rinse and repeat alan - List info/subscribe/unsubscribe? See http://www.freeradius.org/list/users.html
