actually, I just find out that this seems a 4.4 issue, compiled with 4.3 the gdb session just goes fine... I also seem to be able to debug small examples with either 4.3 or 4.4, just CP2K seems to cause troubles (as usual ;-)
I've filed PR39073 for this, somehow hope this can be solved before release (ugh.. show it is not Fortran (I've made it debug) and declare it P1?)
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=39073
