Flash it anyway.
Erm, no. Please check first the readme file for V11 firmware upgrade, and decide if you need it.
The DENEB firmware version can be found out by checking the autoconfig serial number with a tool like Scout (recommended tool). Choose "expansion", click the DENEB entry (#3643 #10), and see the serial number there in decimal.
Mine (for example) says 3820162831 here, which is in hex 0xE3B30F0F.
Which means: 0xE3B is me, 3 is Zorro III firmware, and 0F0F is my beta firmware marking.
The #3643 #19 entry says 3820949263, which is hex 0xE3BF0F0F.
Which means: 0xE3B is me, F is FlashROM card, 0F0F is beta firmware.
Sorry, I haven't a real V11 running here in my setup right now (playing with VHDL :-) )
This is also described in the FAQ section on my website, just as a hint ;-)
Michael