Chart title date format

[RobBroekhuis]

An interesting one: I have a chart with a date as the x-axis. The date format is mm/dd/yy. The chart is on a separate chart sheet. The sheet has a Chart_Activate event handler which checks some worksheet data and, if necessary, adjusts the series data ranges to accommodate new data. This all works fine.
Here's the funny thing: when I the chart handler makes an adjustment, the date format goes to mm/dd/yyyy. When I leave the sheet and come back in again, it's mm/dd/yy once again. Any ideas why it temporarily gets out of whack?
Rob