I'm practicing 华东师范大学 and the character I often forget is 范 but sometimes Skritter won't let me erase the character in the middle of a word (the option is grayed out). Not sure what the graying out logic is as I think I'd always want the erase button to be available.
It stays grayed out even if I go to the next word and hit back.
I'm using the new practice page.