Please describe the problem:
When attempting to rename files in a folder containing files that are being
thumbnailed, focus is repeatedly 'stolen' from the file being renamed by the
thumbnailing process, even when it is  a different files(s) that are having
thumbnails generated

Similarly, attempting to rename a file while thumbnailing is in process
terminates the rename operation (even if you are halfway through typing the new
name) when the thumbnail is complete.

Steps to reproduce:
1. go to a folder full of unthumbnailed video files
2. while thumbnailing is in progress, attempt to rename one or more of the files
3. get annoyed at your inability to do so easily


Actual results:
rename operations randomly 'quit', leaving you with a half-renamed file and
frustrated

Expected results:
thumbnails should be updated in the background, and should never interrupt an
in-progress operation such as file rename

Does this happen every time?
Every time thumbnail generation is in progress, yes

Other information:
Most noticeable with video files