WPF application issues on AMD CPU vs Intel

I'm not sure if I should toss this on SO or not, I don't think its code based, so I'll start here.

We are having an issue in the testing of our new product when using on an AMD CPU vs Intel. The app has terrible screen painting issues and overall runs like a slug. This is reproducible. We have an AMD (C-60 APU) based Acer netbook in house, as well as our Azure instances using Opteron CPUs.

It's a WPF application connecting to a SQL database. If I spin up a low powered Intel based Hyper-V VM in house to match the Acer hardware specs, it runs perfectly fine. If I spin up an Amazon S3 server that is matched in specs with an Azure server, the Azure one has the same performance issues with its virtual Opteron CPU as the Acer does. It makes no difference if it is 2 core CPU or 10. 3GB of memory or 15GB. It appears to be strictly CPU brand based.

I know this may be an oddity, but I'm hoping someone has seen something like this before.