Date formatting not working when date is linked from another sheet

I'm updating an old spreadsheet so dates are now being pulled from another sheet within the same book. Previously the date was entered by hand in two places. The linked date is not accepting the cell format of Mmm-yy. Since this is pulled into a chart, it has to be in the correct format or the chart is messed up. Any ideas why this is causing trouble?

Can you attach a sample workbook showing the problem?

Sample for Forum.xls Here's a cut and paste that shows the problem. I can't post the actual document. Thanks for looking at this.

I searched through the forum and figured out how to format the linked date (see the Sample for Forum for the exact issue). When I use =IF(A6="","",TEXT(VALUE(A6),"MMM"&"-"&"YY")) I get the format I needed - "Jan-12" . The key was using the VALUE function to get the raw date that I could break out of the linked format and impose my own.