I have a phone mask editor in a web grid and it seems to be doing what I want with IE 7 and Safari but sometimes displays wrong in FF3.

When I have a value in the phone number field is behaves correctly most of the time. Usually the phone number is displayed with the mask and I can edit using the mask. However if I select a row that does not have a phone number value once I click into the phone number cell it displays a blank textbox plus the masked text to the immediate right. Once I've done that then even rows containing phone numbers display with a normal text box filled in the the phone number plus the masked textbox to the immediate right. Sometimes I even get that behavior the first time I click into a valued phone number cell.

If it matters, this grid has 2 bands and the phone number is in the child band

 I'm using version  2008, Vol 1, CLR 2.0

Have others had issues with masks and FF3? Any suggestions would be appreciated. Thx