It has been 48 hours and I believe the main PC total is correct, but if both are grabbing the same info, does anyone know why it could be so off?
The problem is likely that you are misunderstanding a detail specific to how Bitcoin works.
Your PC's wallet for the Bitcoin.org client doesn't hold bitcoin in "an address" your bitcoin holds transactions for many addresses.
As a result, if you try to monitor the wallet balance from another tool, such as that Android app, it will not stay in synch because it doesn't know all of the addresses that the Bitcoin.org client holds.
There is no good method for monitoring the balance of the Bitcoin.org wallet, other than the Bitcoin-qt client itself.
If you want to be able to access a wallet from both your PC and a mobile client, use a wallet that support that.
For instance, Blockchain.info/wallet is a hybrid EWallet that can be accessed from the web as well as from the Blockchain for Android (and for iOS) mobile client. That service stores only an encrypted copy of your wallet so the site itself doesn't have access to your private keys.
There are hosted (shared) EWallets as well ... Paytunia's wallet is accessible from the web and from Android.