MAS is peskying about Refunding.

See the following Forum posts:

• First analysis of the log.
• Where I finally understood the problem

A probable solution is to update MaxAmount to be equal to Amount when updating the Refunding.

EDIT: I was wrong on my forum posts about MAS - it's not trying to handle hidden resources, it's calculating the current mass of a PART and, so, it needs to take hidden resources into account.

I forgot to close this. Closing.

An attempt was implemented on 5b735ba .

However, I just realised that Refunding can have negative amount (to handle situations where KSP is refunding too much, instead of too few). I hope MAS won't get picky on this too.