Spell.dbc editing...

I ham currently trying to get some custom spells into spell.dbc, I use DBCUtil.exe by nneonneo. The problem is is that I use it to convert Spell.dbc into Spell.csv, in which it goes from 45,000 KB to 29,000 KB. I edit it with notepad, and when I am done, I use the DBCUtil.exe to turn it back, however after 61%, it gives the error:

Code:

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Traceback (most recent call last):
  File "DBCUtil.py", line 289, in ?
  File "DBCUtil.py", line 89, in ReadCSV
ValueError: invalid literal for long():

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Anybody knows what's happening?

Thanks :)