Only the Votes entity set has this problem.
e.g. https://data.stackexchange.com/stackoverflow/atom/Votes
500 server error
<?xml version="1.0" encoding="iso-8859-1" standalone="yes"?>
<error xmlns="http://schemas.microsoft.com/ado/2007/08/dataservices/metadata">
<code></code>
<message xml:lang="en-US">An error occurred while processing this request.</message>
<innererror>
<message>The 'VoteTypeId' property on 'Vote' could not be set to a 'Byte' value. You must set this property to a non-null value of type 'Int32'. </message>
<type>System.InvalidOperationException</type>
<stacktrace> at System.Data.Common.Internal.Materialization.Shaper.ErrorHandlingValueReader`1.GetValue(DbDataReader reader, Int32 ordinal)
at System.Data.Common.Internal.Materialization.Shaper.GetPropertyValueWithErrorHandling[TProperty](Int32 ordinal, String propertyName, String typeName)
at lambda_method(Closure , Shaper )
at System.Data.Common.Internal.Materialization.Coordinator`1.ReadNextElement(Shaper shaper)
at System.Data.Common.Internal.Materialization.Shaper`1.SimpleEnumerator.MoveNext()
at System.Data.Services.DataService`1.SerializeResponseBody(RequestDescription description, IDataService dataService)
at System.Data.Services.DataService`1.HandleRequest()</stacktrace>
</innererror>
</error>