Hi Juan,
thanks for the info. With my report I was just trying to give an idea where to may start searching for the problem .
I have like + 50 shortcuts from other programs on my desktop and all have their own graphic symbol and none of them did ever disappear , I installed Maxim DL ages ago and the filename icons
(graphic symbol ) for FITS files are visible and stable since ages, but in PI (for xisf files) they disappear all the time since the last update , but it is not impossible a other program or setting is causing this.
/Thomas