DSL Embedded :: German umlaute are only shown sporadically

Hi all,

I am currently trying to solve the following problem:
DSL is installed on a 256 mb compact flash card. Its running in a touchscreen afterwards, with a single selfmade application on it. German umlaute are only shown sporadically on buttons, windows etc (on application as well as on progs running in X), they are being replaced by a question mark. There seems to be no regularity or order (like all in one line or anything) in showing the umlaute or not...at least not in my eyes...on some buttons they work, on others they wont. The umlaute work in a shell though.

Any ideas? Im quite new to the world of Linux, so if you have an idea Id appreciate it if you express it as simple as possible....;)

thx for reading this,
Mara

original here.