SymEfa.db locked file on external USB hard disk

I’ve had a search through the forums for this and have come across similar and varying symptoms and outcomes so I wanted to seek clarification on what the outcome was for this file being locked and how to release this file lock. I’m using NIS 2011 on Windows 7 and I should emphasise after reading the similar posts that I don’t use any version of Ghost and I am not experiencing any errors in relation to corrupt or permissions related problems with the above file. I also don’t experience any BSODs. I just want to be able to safely remove an external USB hard disk without being told that the above file is in use inside the System Volume Information\EfaData folder. From other posts which mention the above, there were varying responses - either to disable Auto Protect before safely removing USB device, to turn off Removable Media Scan or to turn off Tamper Protection. Was there ever a definitive response to this file and how the process locking this file could be ended before safely removing USB drives or any improvements in NIS 2012 or beyond to solve this issue?