When accessing the backend admin section of VM invoice and clicking on the "fields tab", I try to enter data like my phone number. However, when clicking on the text field next to "Phone" (or anywhere else). it simply deselects the field immediately and does not allow me to type anything.

I have tried changing the status of "Phone" from hide to show and then to enter the data, but it still does not work. As soon as I select the field, it automatically deselects the field so that nothing can by typed in it.

I am using firefox 4 as my browser.

Please help.