Originally Posted by vermontcathy
Thank you for your assistance. I will consider Dropbox. I assume the single-writer rule means that you shouldn't have Calibre open in both places at the same time.
Yes - Calibre assumes it has exclusive access to the database, so trying to update on two computers at the same time can cause conflicts. There is a long-running background activity to remove this restriction, but it is unlikely to produce any results in the near future. If you make a mistake and accidentally run calibre on two systems at the same time and thus you DO get sync conflicts then using Calibre Library Maintenance facilities can help with resolving them.
Dropbox is the cloud solution that is most commonly use. However if I remember correctly other solutions such as SkyDrive and SugarSync also work OK. I am guessing that at some point GoogleDrive will be updated to stop it mangling filenames (but being Google who knows