Annoying problem in the edat file

[Vaaal]

Hi, I have a strange and terribly annoying problem in the edat file. Basically what happens is that the onsetToOnsetTime of one of the frame just stop recording. This happens after aroung 23/24/25 trials (not always the same!). For example, until the 22th trial everything is recorded correctly, from the 23th on the frame.onsetToOnsetTime is just 0.  All the trials are the same, and I didn't notice anything in particular that could trigger the strange behaviour in the 23th/24th/25th frame. I am REALLY confused! Plus, I am running some subjects and I really need that numbers there, so I also have a timing problem...
Do you have any idea?? I would be really grateful!
Best Regards,
Valerio