Do you see the same thing on other partitions?
No idea what caused this as yet...
Only on FAT
This seems to be connected to mtools mtools_default_codepage in config.c being 850?
Maybe you could try with glibc_gconv loaded?
With glibc_gconv loaded the issue is not present.
Further TestsHere, there is an existing system
TC v 4.1
Gparted v 0.6.2
mtools v 4.0.12
glibc_gconv is not installed
In this system the reported issue is not present.
Replacing mtools in the new (problematical) system
TC v 4.7.2
Gparted v 0.13.1
mtools v 4.0.12
glibc_gconv is not installed
In this condition the reported issue is still present.
Does this indicate the cause may not be mtools? Perhaps glibc_gconv is somehow working around the problem without addressing the cause.
Edit
Just musing. Might this have a bearing...
Working system
uname -r
3.03-tinycore
Problem system
uname -r
3.0.21-tinycore