How to record precisely timed videos?

I measured the temporal precision of my videos by recording atomic clock time. Whenever I record a video (using the start(vid)/wait(vid, Inf) commands) I get the correct number of frames, and the file duration is correct, but the real time showed in the recording is a few extra seconds longer and there are some time jumps, so a 1min recording will capture 1min1sec of real time and skip a total of 1sec during the recording, a 15min recording acquire even up to 7sec more, and skip a total of 7sec at some points during the recording. This happens both when recording with a hardware trigger and by using start acquisition in imaqtool. This makes the videos unusable for my purposes.

What could be the reason for this behaviour, and are there any better ways to record videos @~25FPS?

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I work with Windows7, using the Image Acquisition Toolbox and Matlab vR2014a with Basler ace acA1300-60gm (<http://www.baslerweb.com/en/products/area-scan-cameras/ace/aca1300-60gm>)