clicking on Thumb in geeqie open next picture

[Lanzi]

I have reinstaled siduction from the latest iso. I see a strange behaviour in geeqie (and olny there):I have soe pictures in a folder. If I click on a pic to open it, the next one in row is opening.
This is really disturbing. gthumb (also a gtk program is not showing this behaviour).
Can anybody confirm this, or knows if its a wrong setting?
Thanks