PPTP VPN Shows Connected, But Not Syncing

I have several different users that when they connect up via PPTP VPN, it will show that the VPN Connection has been established, yet Outlook will inconsitently connect to Exchange and Mapped Drives. Even in times when the bandwidth utilization is low, we still have issues. The connection hits our Cisco 2800, then to a Netgear GSM7212, then to our DC, Exchange, and File Server. No dropped packet errors in any logs. WTF?