On behalf of the Rockbox developers, I'm very pleased to announce that Rockbox 3.9.1 has just been released! This is a bug fix release for Rockbox 3.9.
Go here to download the installer (individual zips are also available): http://www.rockbox.org/download/
Read up on the bugs fixed in 3.9.1: http://www.rockbox.org/wiki/ReleaseNotes391
And above all, enjoy!
P.S. As usual it may take a little while for the download mirrors to catch up, so if you have any problems with the download, please give the builds a while to propagate first.