There's no IP banning - only temporary 60 second bans for your worker if you submit a lot of invalid shares at once (like using 64 difficulty with high hashrate miners on block changes). When you create a new worker, you have to wait 60 seconds for it to be sync'd to the pool servers.

If you're still having trouble, can you join our IRC channel? It may be easier to help you there. Its ##ipominer on Freenode IRC network.