I'm not to familiar with Ogg files, but from the info I have, the Q2 will support Ogg(Q0~Q10) files.
As for the firmware, the unit should have updated to the newest firmware, since it seems you have followed the directions correctly. Did you put the firmware file in the root directory of the player (that is to say, making sure not to add it to any folders found on the player). Are you able to connect the player to your PC and remove the firmware file from the player? Are you able to power it back on afterward?
my Samsung YP-Q2 Video/Audio Player arrived today. But it didn't play .ogg audio files as expected, it just spit out "unsupported file". So I thought a firmware upgrade would solve it. I downloaded the latest firmware (1.23) for the Q2 from the Samsung Download Center and exactly followed the instructions in the manual. I extracted the archive, copied Q2Update.dat to the player, disconnected it from the usb cable, and turned it on.
Then there was a message "Updating firmware". After a few seconds it disappeared and the player turned off.
I tried again. Again there was the message "Updating firmware" which disappeared again and the player turned off. I also discovered that shortly before it turns off it says "Upgrade failed". I repeated this many times, always the same result. I can't use it now anymore
What can I do to recover the original firmware and get the player in a useable state?