Hello all, Thank you for your quick and constructive help so far. It is really helpful - at least I know that it is not my fault..
All characters work well in all other applications, so this is not a problem with xorg- or X11 configuration. The workarounds sound well, unfortunately they are not acceptable for the usual textprocessing user who has no clue about the underlying processes of programmes and is not at all inclined to use shortcuts or ERT. As a user belonging at least partly to that group I am simply afraid to kick out my qt-version and trying to compile it myself. Good heaven, knocking down my system is the most probable thing that is going to happen and the least desirable at this moment ... The most suitable solution in my case seems to be the one with lyx for xforms - the only problem being that I have not able so far to complile the src.rpm of libforms due to allegdly missing xpm. Well, I will have another look at the install file - it is the first time I am forced to compile something so this is probably my mistake. I am sorry I cannot contribute a single line of code to this great programme the lyx developers gave to the open source community. Thank you so far for your work - it is really appreciated! Christopher