In this post we described a bug in the Ajax Control Toolkit v1.0.10920 that caused the AutoComplete Extender to behave incorrectly. The main problem was that we were getting ‘undefined’ as the list of suggested words when using purely numeric values, as shown in the following figure:
Fortunately, the Ajax Toolkit Team managed to solve the issue in changeset 27752 so we do not get the list of ‘undefined’ options anymore*.
Note: To use the new toolkit version, simply extract zip file, load the "AtlasControlToolkit-27752DevelopmentAjaxControlToolkit.sln" solution in Visual Studio and run it to generate the assemblies.
*However, take into account that the first issue mentioned in this post has not been solved yet (No autocomplete list is shown until you hit the backspace key).