Cannot open high resolution photos after deleting low resolution versions

[Batoloco]

Hello,
Did I miss the memo that says deleting lo-res photos will somehow not allow one to open the hi-res versions? I have the 1520 connected to my Windows 7 PC (via USB) and wanted to keep the hi-res versions only, so I deleted the lo-res ones. The hi-res files still appear as physical files in file explorer with multiple megabytes but no preview/ thumbnail (same as before). I can't transfer them to an empty folder on my Desktop or to Imgur, nothing happens, not even an explanation. I checked my recycle bin and the lo-res files are no where to be found. All this is very counter-intuitive to me (and annoying as all hell). Anybody else have this issue?

 

[Skamath]

Apparently it is a feature of the phone. Same here on L1020. High Res and DNg only visible on the comp and whie editing I believe it is only the Low res ones that you are editing. and when in USB mode whatever you delete doesnt go to recyle. It is GONE