#3 Tagging fails because file is locked (intermittent)

[felixwatts]

Sometimes when we try to write the tags upon download complete, the file is locked. pp first writes the file, then closes the file stream, then tries to open it again for tagging so its possible the lock is still held by pp when the tagging begins (despite the file stream having been flushed, closed and disposed). Another possibility is that a virus checker with on-write scanning has locked the file when pp releases it after download.

I suggest using this workaround: if we cant open the file for tagging, wait some milliseconds and try again, repeat this a small number of times, if still no success log it and give the user a Retry/Cancel.