Photoshop doesn't save files properly

Recently I have noticed some of my psd files, after save and close, doesn't keep my last changes I made after reopening. Any error message or similar things doesn't appear. I'm using Photoshop v14.0 with Windows 10 by the way.

This is a really big issue, I spent many hours working with photoshop and I don't want to throw all that work in the bin. I think this started since the last Windows update. At least I would know if there are more people who notice this problem with their experience with photoshop recently.

Thanks.