I was running file monitor for a while. Don't believe I got any file change emails, even when plugins were updated. But I noticed my site was having a LOT of problems. wp-options was getting corrupted all the time and the blog was VERY slow or offline due to corrupted tables.
I found that my wp_options table was over 500MB!!!! Turns out this was due to almost 650 wpfm_listing entries with the hash keys for every file in the site (it's a big site - lots of plugins) When I deactivated the plugin and removed all of the wpfm_listing entries, suddenly my wp_options table returned to a much more sane 1.8MB.
Why so many entries? Seems like you'd only need a couple. Also - looking at the way the data was stored, there is a TON of redundant data stored in the entries - namely the root directory, which should never change. If you extract that out into a separate DB record, it would likely trim the hash entries WAY down. You may also want to consider checking the size of a hash before you insert it into the DB so you can perhaps split them up into manageable chunks.
Now there seems to be some other issues going on with duplicate entries in wp_options from other plugins as well. But File Monitor was the worst by far. And trimming down teh size of the blob may make thigns much easier on larger blogs.