Interval timer on d600

[barry.milford]

I'm trying to bulb ramp on my D600 but as the countdown reaches about 15 secs to go (taking a photo every 60 secs) the intervalometer switches itself off. Can't figure out why? Anyone any ideas? Thanks.

[dmilligan]

What version of ML (include date please)?
What are your settings?
When exactly does this happen?

Please be more specific.

FYI, bulb ramping was removed and replaced with AutoETTR