Ok... This is getting way too anyoing, i thought it was about time i posted my problem here.
Well.. Basically, the thing is: both file explorers (explorer and dopus) crash when i open a directory that has many big files. (i think it mostly happens with .avi movies). What most intrigues me is that this happens not only when i access the disk but also if the files are on a dvd. As soon as i open that folder, the file explorer crashes.
Also, i am able to open the files (both by command line, or by the "open file" dialog of my video player).
Further notice that if i use winrar to browse to the directories in matter, it doesn't crash, which means it's a file-explorer related issue.