NetAuthsysagent or cannot access other macs on network

Hi,

So here is my issue: I have an airport extreme with a 1TB harddrive and an iMac with Moutain lion that is connected to a 3TB drive all shared. I added a Macbook Air 11" to the mix and it worked beautifully to connect to all network drives and the iMac but recently when I try to go into my network drive or the other iMac I dont' get anywhere. All it does is increase my processor output with no actions. I check my Activity Monitor and notice that NetAuthSysAgent is taking over 100% of my CPU. Mind you I have the i7 2.0 GHz with 8GB RAM so this shouldn't take too long but keeps on failing on me.

I have to go and force quit the netauthsysagent or my computer starts heating up because it keeps on trying to process who knows what....

I have wiped out my computer and re-installed (Clean) ML and still having this issue.

What else can i do to connect to my network drives?

Thanks for your help!