Saving Changes on Projects

I did a search on here and couldnt find anything about this, When im working on a project i saved from the night before, and i make changes to it, whenever i save it in the same folder I will get 'DIRECTORY ERROR'. This dosent happen all the time, but when it dosent it will save really quick and when i open the folder say the next day, no new changes i made were saved. I was just wondering whats goin on

hehe damn do i feel like a fool i didnt even see ur post. i just got done posting about directory error, ya i got the same bug poppn up as well