I've been having similar problems.

I thought I found something on google awhile back about a limitation of the
amount of data points you could have in an Excel 2007 file before it would
not show the data when printed.

I just tried printing a graph with 5,522 columns and 6 rows. I tried it on 3
different printers and by printing it to a pdf file. Every one of them did
exactly the same thing; a nice graph, but no data!

The only solution I've found for the problem is to open it with Excel 2003.
After doing so it will print just fine. This is becoming more and more of a
problem as I'm processing more data and they are forcing us to upgrade all
our machines from 03 to 07. Is there something I'm missing?