I accidentally found that there is a really really stupid and useless short cut 'ALT+X' that exit eagle. Really annoying to see eagle disappear in a middle of my work.
And unfortunately, I assign other short-key near the X key (on French keyboard, the X is just near the ALT, so all my 'ALT +' sohrt-cut are high risk short-cut !!!!)
Why on hearth there is still a short-cut like that ?
And last point : if someone need a short cut (in addition of the ALT F4) you can assign it.
SO PLEASE REMOVE THAT STUPID SHORT CUT !!!!!!!