[Industrial One]

I'm editting a really long WAV file with periodic silences -- well not
exactly, they are short pauses with bigass de-amplification of the
audio, which I can recover by amplifying it 80 DB and denoising.
Problem is, Izotope is a faulty editor and crashes for no ****ing
reason at times. Losing 6 hours of hard work made me quit for 2
months. So anyway, because of this I have to save every now and then
so I don't waste too much progress if it crashes, but I noticed that
every time I do that it adds more noise. In fact, I only noticed 3/4
of the way thru when it got really bad. Almost all the recoverable
signal has been ****-canned by the constant piling up of noise, so now
I have to trash the whole project AGAIN and start from the beginning.

So my question is, how do I save without adding any more noise? Will
converting the original to 24-bit and editting from there help? I can
convert to 64-bit if necessary.