2013.12.24 00:14
STEP 1
Check two keys in the regedit table
Key1 HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\Explorer\ShellIconOverlayIdentifiers ;
Key2 HKEY_LOCAL_MACHINE\SOFTWARE\Wow6432Node\Microsoft\Windows\CurrentVersion\explorer\ShellIconOverlayIdentifiers
If Key1 more than 10 (or 15?)
Delete some, e.g.
Offline Files
TortoiseLocked
TortoiseIgnored
TortoiseUnversionsed
Or rename Dropbox Ext so that it will come first alphabetically.
If there were no DropboxExt keys, from the DropboxExt1 until DropboxExt4, find the original in the Key2, copy them to the Key1
STEP 2
Restart or Log off
Then you will find your pretty little green overlays :)
http://etoilefr.wordpress.com/2013/03/25/fix-dropbox-icon-overlay/