Question ... why isn't HEZBOLLAH helping HAMAS?

Because they are scared of the Israeli's.

They've seen what they did to HAMAS and they are scared!

They know...You mess with the Bull, you get a Salchicha.

Because Hezbollah don't even like Hamas you idiot!
Hezbollah are shia, Hamas are sunni.

This, but it sometimes seems like it would be in their best interest to combine forces in certain situations such as the one currently at play in Gaza.

Also, i think Hizzy want to keep the integrity of it's armed forces intact, and keep stockpiling for the next big event.

Yep: The enemy of my enemy is my friend, untill one of the enemies kills off the other one and then the enemy of their enemy is my enemy again!!!

Doesn't Iran ultimately give orders to both ?

Hezbollah still may choose to open a northern front, but then Israel may also to choose to open this front. There are great risks in the engagement for both sides.

I think we wait for the ground invasion and then we will see what Hezbollah will and will not do. For now, they choose the value of public opinion and what they see as political gains from Israel's action in Gaza and the decreased attention paid to their Allie Syria.

Exactly why should Hezbollah support hamas while the Sunni Arabs are selling them out.