d700-first shoot

Well, as per my post last week I had a full 2 day shoot with the new D700-Sigma 120-300f2.8 combo.
In brief vey successful BUT!! Isnt there always a but.I expected a few settling in issues so here goes.
Approx 2500 shots in jpeg (mainly due to sise constraints) VERY low light conditions. My best results seem to
be Avf2.8 iso 3200 - 6400 on camera hi noise control.Over the two days I had about 50 "shutter failures" this left an image completely black with shutter speed showing but no apperture recorded.So I returned to store of purchase and they claim dirty cotact camera to lens--sounds like crap to me but I will give it another run this weekend.I would like to post a couple of images but am struggling with this aspect at the moment--cheers jim-inmotion
In brief vey successful BUT!! Isnt there always a but.I expected a few settling in issues so here goes.
Approx 2500 shots in jpeg (mainly due to sise constraints) VERY low light conditions. My best results seem to
be Avf2.8 iso 3200 - 6400 on camera hi noise control.Over the two days I had about 50 "shutter failures" this left an image completely black with shutter speed showing but no apperture recorded.So I returned to store of purchase and they claim dirty cotact camera to lens--sounds like crap to me but I will give it another run this weekend.I would like to post a couple of images but am struggling with this aspect at the moment--cheers jim-inmotion