Thank you for writing.
Please note that in order to continue receiving support from Telerik representative, you need to provide us with the requested information in the "MeasureOverride returned NaN: Telerik.WinControls.UI.RibbonFormElement
" thread, which you have opened. This can can be found in your Telerik account.
Once you provide us with this information, please let us know that you have pending threads and we will address them accordingly.
As a gesture of goodwill, here is the answer to your current inquiry. The auto-complete works only with the text property of the items and this scenario is not supported. I logged it in our issue tracking system as a feature request. We will address it in one of our upcoming releases. I can use this link to track the issue status.
I cannot propose the work-around due to internal implementation of the control.
I am looking forward to your license details. For your convenience I converted this forum thread into a support ticket as well.
the Telerik team