Hmm. I emptied the pictures folder and tested again. The pic files have the running three digit number in the file name. For some reason at the moment sf cam is naming files with numbers ending 04* and cameraplus 05*.

The problem seemed to get fixed after I took enough pictures with sf cam so that the number got bigger than what cameraplus was producing. Now both apps name the files like they should UNTIL I deleted a picture taken earlier. It was number 056. The newest pic was number 063. Then I took a pic with cameraplus and got a picture numbered 064. Then I took another pic with sf cam and now it replaced the picture number 064. So the problem comes if you delete an older pic, it seems.