Server Error Solution

Windows 2003 Server ASP.net 2.0 (Visual Basic) MS SQL 2005 I use a shared hosting plan for my web site. I am getting an error message. Do you have a solution that I could purchase? Description of how I get the error message: This is a data driven web site. A web page is open, but is not being used (nothing is clicked for about 20 minutes). Then, after 20 minutes (or more) I click something to change the data. Then I get this error. I refresh the page, but the error remains. Then I reload the page. Then page looks OK, but the data has not changed. Then I click to change the data and then the data is updated. Thanks Server Error in '/' Application. Validation of viewstate MAC failed. If this application is hosted by a Web Farm or cluster, ensure that configuration specifies the same validationKey and validation algorithm. AutoGenerate cannot be used in a cluster. Description: An unhandled exception occurred during the execution of the current web request. Please review the stack trace for more information about the error and where it originated in the code. Exception Details: [login to view URL]: Validation of viewstate MAC failed. If this application is hosted by a Web Farm or cluster, ensure that configuration specifies the same validationKey and validation algorithm. AutoGenerate cannot be used in a cluster. Source Error: The source code that generated this unhandled exception can only be shown when compiled in debug mode. To enable this, please follow one of the below steps, then request the URL: 1. Add a "Debug=true" directive at the top of the file that generated the error. Example: or: 2) Add the following section to the configuration file of your application: Note that this second technique will cause all files within a given application to be compiled in debug mode. The first technique will cause only that particular file to be compiled in debug mode. Important: Running applications in debug mode does incur a memory/performance overhead. You should make sure that an application has debugging disabled before deploying into production scenario. Stack Trace: [CryptographicException: Padding is invalid and cannot be removed.] [login to view URL](Byte[] inputBuffer, Int32 inputOffset, Int32 inputCount, Byte[]& outputBuffer, Int32 outputOffset, PaddingMode paddingMode, Boolean fLast) +1488620 [login to view URL](Byte[] inputBuffer, Int32 inputOffset, Int32 inputCount) +306 [login to view URL]() +30 [login to view URL](Boolean fEncrypt, Byte[] buf, Byte[] modifier, Int32 start, Int32 length, Boolean useValidationSymAlgo) +154 [login to view URL](String inputString) +152 [ViewStateException: Invalid viewstate. Client IP: [login to view URL] Port: 10973 User-Agent: Mozilla/5.0 (Windows; U; Windows NT 5.1; en-US; rv:1.8.0.6) Gecko/20060728 Firefox/1.5.0.6 ViewState: 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...] [HttpException (0x80004005): Validation of viewstate MAC failed. If this application is hosted by a Web Farm or cluster, ensure that configuration specifies the same validationKey and validation algorithm. AutoGenerate cannot be used in a cluster.] [login to view URL](Exception inner, String persistedState, String errorPageMessage, Boolean macValidationError) +116 [login to view URL](String inputString) +251 [login to view URL](String serializedState) +4 [login to view URL](IStateFormatter formatter, String serializedState) +37 [login to view URL]() +220 [login to view URL]() +83 [login to view URL]() +35 [login to view URL](Boolean includeStagesBeforeAsyncPoint, Boolean includeStagesAfterAsyncPoint) +6953 [login to view URL](Boolean includeStagesBeforeAsyncPoint, Boolean includeStagesAfterAsyncPoint) +154 [login to view URL]() +86 [login to view URL](HttpContext context) +18 [login to view URL](HttpContext context) +49 [login to view URL](HttpContext context) +29 [login to view URL]() +154 [login to view URL](IExecutionStep step, Boolean& completedSynchronously) +64 Version Information: Microsoft .NET Framework Version:2.0.50727.42; ASP.NET Version:2.0.50727.42