yes, my files have the .psd extension and i have already set the compatibility on "Always". The strange thing is that in the Ps wellcome screen, i can see the preview but not in Bridge. My workflow in Ps is always the same, more or less but i don't understand where is the issue.
I have the same problem, but I have identified that PSDs that are over 50MB will not save a preview thumbnail nor show it in Explorer. PSDs below 50MB are OK and will display a preview thumbnail in Windows Explorer. I can't find where to change that setting.