I had a number of issues with 255 level spells on my private server. One example was the level 59 shaman spell Incarnate Anew. It was listed as a level 255 spell and under another name. I used Georges Spell Importer on my SQL database found here:
http://www.georgestools.eqemulator.net/
...then I used the spells_us.txt from the SoD client and it resolved all of my spell issues.