Sorry folks, I just came upon this thread...funny how grammar is so important!
Shantinath and everyone, thanks for bringing this to our notice - we only have the mindspace for so much, being a small team. We tend to overlook this stuff far more often than we would like to. This forum is where collective intelligence comes into play!
Much appreciated. Topic made sticky. Addy, thanks for having so much faith in us, you trust that we'll do what's right... but in this case your faith was a bit misplaced! 
It's true, it's based on the blog's IndiRank, and the IndiRank of the voter doesn't make a difference.
Shantinath - I see where you're coming from, and I find myself completely agreeing with you. A little background though, to explain why it was built this way. When IndiVine v2 was created 1 year ago (was it really that long?!), before it had a voting system, it was borne from this thread here. This issue you just brought up actually crossed our minds before, see underlined:
My concern on that thread (copy pasted) :
My only concern is - how do we keep this feature from becoming another Digg or IndianPad? Is there anything we can think of which would differentiate it? The problem with Digg is that you have teams working together to digg each other's posts, etc. Sometime, we may have posts coming to the top which don't deserve to be. Off the top of my head - should we integrate all the above ideas with IndiRank? We can have a ratio to rate posts - user rating + IndiRank. (Maybe 75:20)
Or will integration with IndiRank discourage new bloggers who have a low IndiRank?
And later...
Ok, need to bounce an idea here - about integration with IndiRank - how about we increase the value of a vote based on IndiRank? So if a post gets one vote, and that blog's IR is 45, then the vote is increased by 1.4. (Displayed values will be rounded off)
So you'll see now why it was built in this manner. We actually did have gaming when the new IndiVine was launched, where 1 blogger with 5 blogs will create a separate profile for each blog, open each profile in 5 browsers and vote for the same post. Initially, we would have had a lot of these posts coming to the top of IndiVine if it wasn't for the integration of IndiRank - thankfully, top ranked bloggers don't need to resort to those tactics!
However, in the past few months, we've discreetly taken care of this problem.
So I guess it doesn't apply anymore - and it makes our original fears/logic less relevant.
Moving on, how do we address this? If we attach the value of a vote to the IndiRank of a voter, then what about a voter who has multiple blogs? Do we take an average? Will it increase the number of spam requests targeted at higher ranked bloggers with "please vote for my post" requests?