ODP.NET

Please help. I have been fighting this for several days.
Trying to implement a SharePoint web part that calls Oracle using ODP for NET 2.0 11.1.0.6.20
When I call the page that includes the web part, it shows that Oracle.DataAccess.Client threw an exception.
On the SP server, the error detail is:
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System.TypeInitializationException was unhandled
Message="The type initializer for 'Oracle.DataAccess.Client.OracleConnection' threw an exception."
Source="Oracle.DataAccess"
TypeName="Oracle.DataAccess.Client.OracleConnection"
StackTrace:
at Oracle.DataAccess.Client.OracleConnection.Dispose(Boolean disposing)
at System.ComponentModel.Component.Finalize()
InnerException: System.Security.SecurityException
Message="Request for the permission of type 'System.Security.Permissions.SecurityPermission, mscorlib, Version=2.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089' failed."
Source="Oracle.DataAccess"
GrantedSet=
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I have added several lines to web.config:
<SafeControl Assembly="Oracle.DataAccess, Version=2.111.6.20, Culture=neutral, PublicKeyToken=89b483f429c47342" Namespace="Oracle.DataAccess" TypeName="*" Safe="True" />
<SafeControl Assembly="Oracle.DataAccess, Version=2.111.6.20, Culture=neutral, PublicKeyToken=89b483f429c47342" Namespace="Oracle.DataAccess.Client" TypeName="*" Safe="True" />
<SafeControl Assembly="Oracle.DataAccess, Version=2.111.6.20, Culture=neutral, PublicKeyToken=89b483f429c47342" Namespace="Oracle.DataAccess.Client" TypeName="OracleConnection" Safe="True" />
<SafeControl Assembly="Oracle.DataAccess, Version=2.111.6.20, Culture=neutral, PublicKeyToken=89b483f429c47342" Namespace="Oracle.DataAccess.Types" TypeName="*" Safe="True" />

to no avail.

Any help would be greatly appreciated.
Thanks!