The problem that you are experiencing is that the router with the floating static route does not recognize that the path to the destination is no longer valid and continues to route over that path and effectively creates a black hole.
Cisco has recently introduced a new feature which addresses this problem. The new feature is object tracking. Depending on the release level of IOS that you are running this feature may be available to you. Effectively what this feature does is to track the availability of some remote object (one way is to set up a ping to a remote address) and if the tracking determines that the object is no longer reachable it can withdraw the primary static route and allow the floating static to be put into the routing table.
This link will give you some information and allow you to start experimenting with this feature:
http://www.cisco.com/en/US/products/sw/iosswrel/ps5413/products_feature_guide09186a00801d862d.html
HTH
Rick
HTH
Rick
