Is it possible to upgrade 4.9.5 to any version of 5.x.x ?

I've tried 4.9.5 upgrade to 5.0.1, 5.2.1 and 5.2.2 - it always fails. Each time I roll back site and sql database.
The database is SQLExpress 2005 and NetFramework 3.5 is installed.
I can install a new site - 5.2.2 but can not upgrade my 4.9.5 site to 5.2.2
Is there a secret handshake I'm missing?

Upgrading DotNetNuke
Current Assembly Version: 05.02.02
Current Database Version: 04.09.05

Upgrade Status Report
00: - Upgrading to Version: 05.02.02
00:00:00.015 -   Executing Script: 05.00.00.SqlDataProvider Error! (see 05.00.00.log for more information)

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Server Error in '/' Application.
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Violation of UNIQUE KEY constraint 'IX_oa_Version'. Cannot insert duplicate key in object 'dbo.oa_Version'.
The statement has been terminated.
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: System.Data.SqlClient.SqlException: Violation of UNIQUE KEY constraint 'IX_oa_Version'. Cannot insert duplicate key in object 'dbo.oa_Version'.
The statement has been terminated.

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:

  <%@ Page Language="C#" Debug="true" %>

or:

2) Add the following section to the configuration file of your application:

<configuration>
   <system.web>
       <compilation debug="true"/>
   </system.web>
</configuration>

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:

[SqlException (0x80131904): Violation of UNIQUE KEY constraint 'IX_oa_Version'. Cannot insert duplicate key in object 'dbo.oa_Version'.
The statement has been terminated.]
   System.Data.SqlClient.SqlConnection.OnError(SqlException exception, Boolean breakConnection) +1950890
   System.Data.SqlClient.SqlInternalConnection.OnError(SqlException exception, Boolean breakConnection) +4846875
   System.Data.SqlClient.TdsParser.ThrowExceptionAndWarning(TdsParserStateObject stateObj) +194
   System.Data.SqlClient.TdsParser.Run(RunBehavior runBehavior, SqlCommand cmdHandler, SqlDataReader dataStream, BulkCopySimpleResultSet bulkCopyHandler, TdsParserStateObject stateObj) +2392
   System.Data.SqlClient.SqlCommand.FinishExecuteReader(SqlDataReader ds, RunBehavior runBehavior, String resetOptionsString) +204
   System.Data.SqlClient.SqlCommand.RunExecuteReaderTds(CommandBehavior cmdBehavior, RunBehavior runBehavior, Boolean returnStream, Boolean async) +954
   System.Data.SqlClient.SqlCommand.RunExecuteReader(CommandBehavior cmdBehavior, RunBehavior runBehavior, Boolean returnStream, String method, DbAsyncResult result) +162
   System.Data.SqlClient.SqlCommand.InternalExecuteNonQuery(DbAsyncResult result, String methodName, Boolean sendToPipe) +175
   System.Data.SqlClient.SqlCommand.ExecuteNonQuery() +137
   Microsoft.ApplicationBlocks.Data.SqlHelper.ExecuteNonQuery(SqlConnection connection, CommandType commandType, String commandText, SqlParameter[] commandParameters) +168
   Microsoft.ApplicationBlocks.Data.SqlHelper.ExecuteNonQuery(String connectionString, CommandType commandType, String commandText, SqlParameter[] commandParameters) +188
   Microsoft.ApplicationBlocks.Data.SqlHelper.ExecuteNonQuery(String connectionString, String spName, Object[] parameterValues) +246
   DotNetNuke.Data.SqlDataProvider.UpdateDatabaseVersion(Int32 Major, Int32 Minor, Int32 Build, String Name) +218
   DotNetNuke.Common.Globals.UpdateDataBaseVersion(Version version) +69
   DotNetNuke.Services.Upgrade.Upgrade.UpgradeVersion(String strScriptFile, Boolean writeFeedback) +122
   DotNetNuke.Services.Upgrade.Upgrade.UpgradeDNN(String strProviderPath, Version dataBaseVersion) +333
   DotNetNuke.Services.Install.Install.UpgradeApplication() +931
   DotNetNuke.Services.Install.Install.Page_Load(Object sender, EventArgs e) +272
   System.Web.UI.Control.OnLoad(EventArgs e) +99
   System.Web.UI.Control.LoadRecursive() +50
   System.Web.UI.Page.ProcessRequestMain(Boolean includeStagesBeforeAsyncPoint, Boolean includeStagesAfterAsyncPoint) +627

 I'm in the same boat. I'm stuck on 4.9.5 with no where to go. I haven't been able to upgrade yet. 

I think I'll give it another shot. I keep hoping that whatever is wacky will get straightened out.... but it hasn't.

I wonder how many people are likewise stuck on 4.9.5 with no luck in migrating a large site over to the 5x version. When a site gets a certain size, a new install is no longer an option.

Ted,

  Unless you are getting the exact same error, you should start a new thread and provide details of the errors you are recieving on upgrade.  We have logged and corrected a number of issues in recent releases, but the only way to resolve your problem is to get very specific details.