Steps to reproduce:
1) Mount an EXT2 partition and set the codepage to 'default'.
2) Create a file with a special character in the filename. I used the character 0x89 (create a text file with the contents 0xE6, 0xB1, 0x89 -in hexadecimal- in it and then copy/paste that character from Notepad into the filename in the Windows Explorer).
3) Try to delete the file.
1) Do the same as above in step 1 but now set the codepage to 'utf8'.
2) Now you still can _not_ delete the file but when you create a new file with the same special character, you can delete the new file.