Commented Issue: ModalPopupExtender prepending comma and stale data to textbox [26259]

I just switched from using version 3.0.20229 of the AjaxControlToolkit to 3.0.31106. This problem did not occur in the earlier version.

When I use the ModalPopupExtender, containing two textbox controls, to edit the text in one or both of those controls, it prepends a comma or sometimes old data to the new value in the textbox.

See attached image.
Comments: I had the same problem then I upgrade to the 4.1.7.123 version of ajax toolkit and everything works fine. Thanks