Libraries repeatedly getting corrupted

I use Endnote X3, and am constantly (every month or so) needing to recover my library because the files are getting corrupted. The library is not all that big, about 450 references at the moment, though I am often adding references to it. Any help with this will be appreciated, since I’m getting really tired of recovering the library and periodically having to put references back in when they get lost during this process. 

Where do you save the library?  Is it in a cloud or dropbox or similar? 

I save it in a directory on my HDD backed up to Dropbox.