while(<DATA>){
if(($_ !~ /^(INFO|DEBUG|ID|\s+)/)){
      print"Line check\n";
}
}

outputs:
--------
Line check
Line check

__DATA__
ID      Run     Timestamp       Entry   Attempt Message Type    Message

13      251     2006-07-06 13:21:14.0   1       1       INFO    Starting for (ActivityId=13, DataSource=dunkle-rs)
13      251     2006-07-06 13:21:14.0   2       1       INFO    Querying remote datasource ...