CMTime parameter is received with unexpected value

Question

I'm trying to pass a CMTime value as a function parameter... My function looks like:

getThumbnailForVideo:(AVAsset *)video
              atTime:(CMTime)time;

so somewhere I'm calling

[instance getThumbnailForVideo:video
                        atTime:thumbnailTime];

If there I print thumbnailTime I see the expected value that in my case is simply kCMTimeZero(thumbnailTime.timeScale is 1, thumbnailTime.value is 0)

But if I print time from within the function, I get a really weird value: time.value is 6089232256, time.timescale is 0.

What am I missing?