1. A method for managing a data cache for a computer system, the method comprising: maintaining a cache for one or more data resources requested by a client process; in response to a request from said client process for a cached data resource: sending a first request to a server process for said data resource; and sending a second request to said server process for an indication of whether or not said data resource has been modified since said data source was most recently cached; comparing the responses from said server process to said first or second requests with the cached data resources so as to identify whether said response to said second request is inaccurate by: comparing, in response to said response to said second request comprising an indication the said data resource in unchanged, said cached copy of said data resource with the copy of said data resource returned in response to said first request so as to determine whether said response to said second request is inaccurate; and comparing, in response to said response to said second request comprising a copy of said data resource, said cached copy of said data resource to the copy of said data resource returned in response to said second request so as to determine whether said response to said second request is inaccurate; and disabling caching for said data resource in response to a predetermined number of inaccurate second requests associated with said data resource are identified.