I am a 12th level, chaotic-good, halfling cleric with an 18 wisdom. I am still playing Icewind Dale 1 but I do have HOW installed and the the Gibberlings 3 fix pack or what ever it is called. My 6th level spell list seems quite limited and only has 4 spells which are:

heal
entropy shield
blade barrier
spiritual wrath

i am missing:

Animal Summoning III
Conjure Fire Elemental
Fire Seeds
Sol's Searing Orb
Harm
Whirlwind

What gives? Is it an alignment issue or something?

All those spells except Harm are Druid only.

Harm can only be cast by evil aligned Clerics, so I assume yours is either Neutral or Good?