Resources lost when training in barracks

I think I have experienced this scenario a couple of times now: I go to the barracks to train units. I request 25 recruits, the hour glass comes, I wait till the hour glass is gone, I request another 25 recruits, the hour glass comes, I request 21 recruits (I do not have enough resources for another full 25 recruits) I press the OK button before the hour glass has dissappeared and now I am only training 25+21 recruits and NOT 25+25+21 and I do not have resources for 25+25+21 as I had a minute ago... :-(

Long story short, I lost resources for 25 recruits and did not get the 25 recruits