This is not a BoxCryptor problem, but rather a (very annoying!) Google Drive bug/issue/feature.
If Google Drive _thinks_ that since the last sync newer versions of a file exist at _both_ sides,
both versisons are retained and copied to either side.
One keeps the original file name, the other one gets the number extension.
By itself obviously a good feature, but I had this happen repetitively while being absolutely sure
those files had not changed (content identical) and had not even been opened on either side.
Only way I found to get rid of these files: open Google Drive (via the web interface) and delete the duplicated, numbered files there.
After the next sync, they should also be gone from your local Google Drive folder and thus from your BoxCryptor drive.
