sybase ase hourly transaction log dump keep growing in size

our dba asked me for more space on database servers since it ran out. I opened my trending graph by MRTG. sure enough, the file system holding the backups has creeping up for three weeks now. however, it grows too fast, something like 80G a day instead of 8G a day I'd expect. with the help of 'du' and 'sort', I found the hourly transaction dump is the culprit. It has grown from 10M each to 1G each in the course of three weeks. reported this back to the sybase DBA. after some digging, he said it is a gone-wild replication thread holding a transaction open, somehow. even nightly full dump failed to mark the db such that hourly dump would cover diff instead of accumulative...