asterisk users - Jan 2005 - Continuously ringing Zap/4-1 TDM11B All of a sudden ?[Urgent Pls]

Dear All,

	All these days I was ahpppily using Asterisk with TDM11B, but from
today all of a sudden asterisk has started acting strange.
The telephone device connected to channel 1 rings continously,

following info is displayed on console

    -- Starting simple switch on 'Zap/4-1'
Jan 28 15:38:58 ERROR[77024176]: callerid.c:261 callerid_feed: fsk_serie
made mylen < 0 (-8)
Jan 28 15:38:58 WARNING[77024176]: chan_zap.c:5414 ss_thread: CallerID
feed failed: Success
Jan 28 15:38:58 WARNING[77024176]: chan_zap.c:5456 ss_thread: CallerID
returned with error on channel 'Zap/4-1'
    -- Executing Answer("Zap/4-1", "") in new stack

Please tell me what must have gone wrong so unnoticed ?

Its very urgent to put it back to work, as i dont have backup plans.

I can send my config files if u wish to look at it.

Eagerly awiating.
Thanks in advance.

Anand