custom fields value corrupted/ wrong if capital letters are used

[isiway]

Hello,

I have a customfield XYZ which has a value "AA, BB, CC".

In the front end, only "AA" ist shown.
If I change the value to "aa, bb, cc" it is ok showing "aa, bb, cc".

Any ideas?
Or at least where is the data read from database and manipulated?

Thank you and greetings from snowy Bremen, Germany.

isiway (Carola)