Thanks you both. I will check the LVM info - supposing I'll be able to access the card from DFSee

So far, I only know that I can check the card by DFSee. I didn't dare to manipulate the card because I am completely new in connecting phones to computers

The card isn't big (256 MB). It's a "micro SD" card but I have an adapter (also sold with the phone) to the normal SD card size. Nevertheless, this means getting the card out of the phone. A simpler solutiuon seems to be FAT32.IFS and FAT32 format.
If I understand well then the card should not contain something that must not be lost. In the worst case, I can connect the phone to winblows and format the card from winblows. Am I right?
Not knowing about that particular phone, I can say the safest way regardless is to format the card in your phone... with windows being the next safest way. My particular phones (Palm Treo 650 and 680 both) would lose or corrupt data on the card if I formatted it in Windows (using FAT32). Once I formatted it on the phone (which seems to also format it to FAT32 - or so Windows tells me), I had no problems using it on either the phone or Windows.
I am not sure what the difference in the format method is - but there was definitely something different, and others on the Palm forums indicated the same problems and solution.
So... I dont know if that applies to you - but regardless, it is still probably safer to use the phone to format a card (if it has that function) since it should know exactly how it needs the filesystem laid out.
Robert