Do forgive if this was reported already.
Just moments ago another PC gave my mage a scroll of Nybor's Gentle Reminder and the very moment I wanted to add it to my spellbook the server crashed and reset.
I remember seeing in IRC similar reports of people trying to scribe a spell into their spellbook and this resulted in the whole server crashing. Apparently scribing them right after a crash or reset does not create a second immediate reset, and the spell can be added.
I do not know if this applies to all the Custom spells, and what exactly might be causing the crash, but I thought I would report this connection.