My X100 has been working fine - I went to use it tonight, turned it on and nothing....tried this a number of times all with the same problem, swapped battery - same problem, swapped the card and all worked fine so continued shooting with alternate card - no issues! All my cards are Sandisk cards and the one in question was the 16GB Extreme HD Video with 30MB/s. When I got home I tried the card in my GX1 and it was fine - then tried another 16GB card in the X100 and it works fine. Tried original card back in X100 - still the same problem so no idea what is going on and would appreciate any ideas before I am tempted to contact Sandisk but as it works fine in GX1 suspect it must be X100 related???? Any ideas?