Hello Aris,
i never get an error with sed. And if i use "-nx 300" command with wed(this is standart in my wed), i get en error. But there is no problem with wed, if i increased nexus(like "-nx 400") Edit: or without nexus parameter. Sorry for bad english.

Edit:
Specs:
intel e7500(c2duo), 2GB ram,WinXP(sp3).