Commented Unassigned: MaskedEditExtender: backspace not working in FireFox [27794]

Is there a reason why the backspace does not work for the MaskedEditExtender in FireFox?
Comments: The next release will be in May. An issue related changeset: [0385bcf](https://ajaxcontroltoolkit.codeplex.com/SourceControl/changeset/0385bcfa37957b20316125159f727f50efbee357)