Why won't my MacPro connect to my iPod touch 2g?!

My MacPro WILL NOT recognize my iPod touch 2g through Discover. When the app is OPEN on my iPod, safari takes several minutes to try and connect but ends up saying "the server isn't responding." When the app isn't opened, safari immediately says "the server isn't responding" so i think it's trying to work but somethings preventing the connection...and to top everything off, I have SUCCESSFULLY connected and transferred files ONCE before. Now, the exact same process fails. BTW both ipod and mac are connected to the same Wifi network, just not to each other. Anyone have a clue what the freakin deal is??