Photoshop :: Layer Not Working When Cloning Multiple Folders?

I have a leayer with a bit map inside a photosop folder in my layers. When I clone it the layer information  just disapears. When I ctrl+alt to duplicate it sometimes the layers are active but there is no artwork at all Layer is visible /eye is on/ when click thumbnail to select objenct in the layer a "No pixels alert pops up".

The only way to be able to get the artwork is use a previous version.No I did not delete the layer, neither any one touch the
 
I'm using photoshop Extended 5.1 (64 bit) on a pc.The original file v.01 was done in a mac photoshop cs3, edited and saved as a in the office pc  (now v.06), I name my files sequentially to be able to back track, (so a filename looks something like this client_project_B01_v03_06.psd )