Sorcerer and Dragon disciple - known spells

I'm confused about number of spels known by sorcerer and Dragon disciple. From description I understand, that number of known spells should be the same for both of them.
Currently I'm playing Black Pits 2. My level 27 Dragon Disciple knows:
level 1 - 4: 5 spells
level 5: 4 spells
level 6 : 4 spells
level 7: 3 spells
level 8: 3 spells
level 9: 2 spells (+5 HLA apells)
According to this tables: http://playithardcore.com/pihwiki/index.php?title=Baldur's_Gate:_Progression_Charts#Sorcerer
the numbers of known spells should be higher. Where is the problém?
Currently I'm playing Black Pits 2. My level 27 Dragon Disciple knows:
level 1 - 4: 5 spells
level 5: 4 spells
level 6 : 4 spells
level 7: 3 spells
level 8: 3 spells
level 9: 2 spells (+5 HLA apells)
According to this tables: http://playithardcore.com/pihwiki/index.php?title=Baldur's_Gate:_Progression_Charts#Sorcerer
the numbers of known spells should be higher. Where is the problém?
1
Comments
Losing one casting per level per day is a ridiculously small disadvantage compared to the massive bonuses gained by the Dragon Disciple.
So known spells should not be reduced for a DD, the situation can be a bug or inconsistency between the game and manual tables. Tried creating a sorcerer and lvl up via console, and does he know more spells per level than the DD when they are at the same level? He should not, from game kit description DD's disadvantage should just be a -1 spell casting per spell level.
does right now, in the game DD have more known spells than a Sorcerer of a same level?
Isn't a DD in BG just a flavored caster?
( @Elminster mentioned that in one discussion)