Created Unassigned: Error when trying to view submitted contact form data [1934]

Recently we've had a problem where we are unable to view contact form data. We get the message that an unfortunate error has occurred. Clicking details produces the stack provided below.

The site is running 3.2 patch 3 and until recently there was never an issue with the contact forms. I can provide the full stack from the server error log if that might help. Any ideas?

InvalidOperationException:
Failed to get value for function 'Composite.Utils.Dictionary.XElementsToDictionary'
Stack trace:
at Composite.Functions.FunctionRuntimeTreeNode.GetValue(FunctionContextContainer contextContainer)
at Composite.Functions.FunctionParameterRuntimeTreeNode.GetValue(FunctionContextContainer contextContainer)
at Composite.Functions.BaseRuntimeTreeNode.GetValue[T](FunctionContextContainer contextContainer)
at Composite.Plugins.Functions.WidgetFunctionProviders.StandardWidgetFunctionProvider.String.SelectorWidgetFunction.<GetOptions>d__0.MoveNext()
at Composite.Plugins.Forms.WebChannel.UiControlFactories.SelectorTemplateUserControlBase.InitializeSelectorElements()
at Composite.Plugins.Forms.WebChannel.UiControlFactories.SelectorTemplateUserControlBase.GetOptions()
at ASP.composite_controls_formscontrols_formuicontroltemplates_selectors_selector_ascx.InitializeOptionList() in c:\inetpub\wwwroot\prodsite\Composite\controls\FormsControls\FormUiControlTemplates\Selectors\Selector.ascx:line 44
at ASP.co
ArgumentException:
An item with the same key has already been added.
Stack trace:
at System.Collections.Generic.Dictionary`2.Insert(TKey key, TValue value, Boolean add)
at Composite.Plugins.Functions.FunctionProviders.StandardFunctionProvider.Utils.Dictionary.XElementsToDictionaryFunction.Execute(ParameterList parameters, FunctionContextContainer context)
at Composite.Functions.Foundation.PluginFacades.FunctionWrapper.Execute(ParameterList parameters, FunctionContextContainer context)
at Composite.Functions.FunctionRuntimeTreeNode.GetValue(FunctionContextContainer contextContainer)
Generated 2014-02-27 14:36