I don't know about the way you're doing it, but so far I've had no trouble saving my whole inventory in one line, nor has hybrid(as far as I know he saves it as one line too, correct me if I'm wrong).
If you want to do it in more than one line heres an example
Code:
for(byte i = 0; i < 40; i++)
{
Charr.Inventory[i] = Ini.ReadString(Section,"Inventory[" + i + "]","0");
}
This way your Ini Files would be like
CharName=Name
Inventory[0]=Yada1
Inventory[1]=Yada2
Inventory[2]=Yada3...
And so on..