The FSTrigger currently stops working if the casing changes on the file being watched.  It stops silently, the build is broke and there is no indication that anything is wrong.  A manual review is required of the polling log to find the issue.  There it does report that the "The computed file doesn't exist".

To help avoid this issue in file systems that are case insensitive, it would be useful to FSTrigger to have an option to set case-sensitivity, or to follow the case-sensitivity of the file system it is monitoring.