Setting loops in STS-3000

[Eurocide]

I noticed that the setting of loop markers in the STS-3000 sample editor is very fiddly.
Sometimes the green marker moves, sometimes not ("protect" mode OFF, of course!).

Current procedure:
- new program
- new keygroup
- import WAV
- open STS sample editor
- init loop
- trying to set markers
- ripping off my hair...

Can somebody confirm this or has a solution before I get bald?

[jupiter8]

Use another program to make the loops.
I never use the STS sample editor.
And i have all my hair still on my head.