Save to .xlsx, the Lion compatible Excel file format istead of .xlx used with older non-Lion compatible versions of Excel and it will work for you. It's an issue with Lion more than it is with FileMaker.
Huh? Excel has nothing to do with Lion.
.xls is the long-term format. If any format were to be supported, it would be one that's at least 7 years old, right?
And, as I'm sure you konw, the .xlsx format was out before Lion was even conceived. It's an Excel xml format, nothing to do with Apple per se.
Thanks for your reply.
P.S. Excel for the Mac 2011 works fine with .xls and .xlsx with z-e-r-o problems. Therefore, it's an issue with FileMaker.