I guess you must be referencing cache application block dll in your project. If you need to use cache block, build the caching application block dll and copy the MemoryMappedFileStream.dll from the bin folder of cache block to your project bin folder and add this reference to your project.
Or Remove cache reference from your project if you dont need it and the warning will go away.
************************************************** ********************
Sent via Fuzzy Software @
http://www.fuzzysoftware.com/
Comprehensive, categorised, searchable collection of links to ASP & ASP.NET resources...