This is very strange problem.
Sorry - I have no experience of this type of problem.
Maybe it has something to do with the x64 operating system.
Does it occur only if the triggering is on but not in the free run mode?
Can you use the single shot mode if the triggering is on and repeat several times?
To improve the compatibility with 64 bit operating systems a 32 bit timer (FASTTime32.dll) is no longer used by the PCSU1000 oscilloscope software.
Here a link to download the modified software to install: velleman.eu/downloads/files/ … e_rev4.zip