Got some sleep and found it right away
Will update you later when I have had a look at the log files.
UPDATE: I did a little more testing, and seems it's the cfw that does it. I tried re-install the original firmware and then everything is fine (removing the custom OSD when running cfw had same issues...)
Long story short; it is not an issue with this OSD, but happens when using 1.02.21 - 0.x.x.x custom firmware.
UPDATE.again..: Seems it's an issue with one or more plugins..disabled them all, and everything is good.
Will enabled them one at a time, and see what happens.