I just read a bit about this because I bought an M4, with v0309. Latest is v000F.
Some people had problems. Google how to see what version you have from within Windows.
It's basically click on computer, right click the M4 drive, properties, hardware, select the M4 drive, properties, details, then select hardware id from the fropdown list. You'll see your version repeated 3 times there.
I decided not to update because I don't see benefits in the update. I'll look closer later.
People who had similar issue as you seemed to have a good update.
Look at the Crucial site for more details.