Moreover it seems to be a problem of timing:
* when I launch, using alt-f2, firefox -profilemanager or thunderbird -profilemanager, I often get nothing. But if I selected 'run in command line', the firefox/thunderbird always appears.
* when I run nautilus-sendto within gdb I rarely get the described error; it seems that gdb slows down a few nautilus-sendto and the problem disappears.
Moreover it seems to be a problem of timing:
* when I launch, using alt-f2, firefox -profilemanager or thunderbird -profilemanager, I often get nothing. But if I selected 'run in command line', the firefox/thunderbird always appears.
* when I run nautilus-sendto within gdb I rarely get the described error; it seems that gdb slows down a few nautilus-sendto and the problem disappears.