i droped 4 databses in sqlserver after this ..in my sql log is showing ............

05/12/2011 08:19:45,spid60,Unknown,SQL Server has encountered 1 occurrence(s) of cachestore flush for the 'Bound Trees' cachestore (part of plan cache) due to some database maintenance or reconfigure operations. 05/12/2011 08:19:45,spid60,Unknown,SQL Server has encountered 1 occurrence(s) of cachestore flush for the 'SQL Plans' cachestore (part of plan cache) due to some database maintenance or reconfigure operations. 05/12/2011 08:19:44,spid60,Unknown,SQL Server has encountered 1 occurrence(s) of cachestore flush for the 'Object Plans' cachestore (part of plan cache) due to some database maintenance or reconfigure operations.
 
I don't n know why its happening , is there any suggestion to prevent this
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