You're not making it any easier. "manualy setting the loop end", what is that? I gave an example of three ways of setting the loop end, all of them are manual, and all of them involve different code, so you have to be specific which of the three you are using. I no longer understand if you use the spin buttons or enter the number with your keyboard. Also, please refer to revision (can be seen in the about dialog) and not version numbers, as 1.24.00.22 spans several revisions. So please download the latest version from the buildbot and try it again, and if it still doesn't work for you, state the revision you have tested and which method (entering a number, clicking the spin buttons or right-clicking the waveform) you used to set the loop point.