Using different masks in a row aren't written

[K-Meech]

When a mask is written, it just checks if a certain name already exists - which for a fixed mask is always 'FIXED_MASK_0' or something like this. Therefore, if you use a new mask for the next registration, it will just re-use the old one as that filename already exists. Need to give some unique name somehow / some way to specify which file it came from.
(at the moment, just wipe the folder in between successive masks)