I reported this a while ago in this thread DBRepair development - #920 by dokuro. There is lots of detail in that thread so I suggest you take a look. To summarise, the tool will ALWAYS report the FTS indexes as corrupt after a scan of a library it done.
I personally see this as a false positive and moreover I reverted the DBRepair tool to version v1.13.02 which does not do this fts check.
