When trying to shrink a file or database I get an error if a backup tries to run at the same time.
"File ID 1 of database ID 21 cannot be shrunk as it is either being shrunk by another process or is empty."
This occurs if I am attempting to shrink a file, data changes are happening in the database, and either a log backup or full backup is ran. After the error happens, I ALWAYS get this error until I restart the SQL Service or take the database offline and online again.
I've seen this error since RTM and still see it in build 3175. I've seen it in Developer Edition, Standard Edition, and Enterprise Edition. I've also seen it in both 32 bit and 64 bit.