Anything that is 7.0.7390.0 and above is Nodo which can't be jail broken at this time unless you unlock using a developer acct or a legit method.
Only other option would be.. if you updated the phone yourself, as apposed to purchasing the phone with Nodo pre-installed, you may be able to roll back to the previous OS version using Zune...then chevron-unlock the device, prevent relock, then update to nodo. That way you have Nodo and a device that is unlocked.
Otherwise, you'll have to wait till Mango, which is coming very very soon (speculation is sometime in Sept), and use the offical Chevron-Mango method when they release it with Mango..but that will cost somewhere between $5-10 usd.
