Internet is down but OPManager doesn't recognise this.

We have a site that is currently experiencing internet problems. It appears as though the ADSL connection has gone down. Thankfully our frame relay link allows me to continue monitoring the PIX however OPManager is not showing any faults. The PIX is monitored and the external IP address is recognised in the interface however because the PIX doesn't see the interface as being down then OPManager is not showing any problems.

I can't find anyway to monitor for when the external IP is not reachable thus indicating that the internet in general is down. Thankfully our old monitoring system is capable of doing this so I knew about the problem but if OPManager can't do this then that is a big worry.

Any ideas?