Shooting slow mo on 5D3.

[AlexRo]

It's ok with continious rec 1080p at 25p. But earlier I was recording at 50p (1728x606) and it did at least 1 min of continious rec without skiping frames. And the icon of buffer in LV was like 6 sections and now it is only 4 sections. Now when I shoot 50p (1728x606) it starts skiping after 10-30 sec I'm using the latest nightly build and transcend 1000x udma-7 (write speed 120 mb/sec). What is the problem? PLease help! I wanna shoot slow mo