I have two columns of values, one with Dates going from 04/31/2004 to
12/31/2006 (one per month), and another column with items per month.

Read another thread which seemed to imply having values stored as
number (instead or in addition to having them as a number for their
format) was important for a line chart to display properly. So, I copy
the number range (for the items per month), paste special, and select
Add. they should be stored as numbers now.

Created a Pivot table under the Data pull-down.

Clicked Chart, and it created a bar chart, which looks good.

Right-clicked, and select Line chart with markers displayed for each
data value.

The problem: the markers display properly, but NO LINE SHOWS.

My manager said he had this problem as of Dec 2006 or so, and could not
figure out why.

Any suggestions on troubleshooting?