Unusual Printing Problem

I have a program distributed to a couple of dozen customers.

I recently made an update to the program involving some revised reports required by the state government.

In all cases the update worked fine, except for one.

In this case one page of the reports (there are 5 reports in all) has experienced an odd bug. On certain of the lines printed (always the same lines), the printing is degraded so that it appears that a space has been written through the middle of the line of print; or over the upper-half of the line of print. The error is not random. Reprinting the report multiple times, or reprinting the report using different data gives the identical result

When in display mode, the report appears fine. Only during actual printing does the degradation occur. All other reports (with far more lines to print) are successful.

I've tried moving the location of the printing on the page, and that has helped some. But still the net result is unsatisfactory. Since this report is being submitted to a local court, the output is unacceptable.

The user's printer is an HP Officejet 6310 All-in-one. Allegedly, this printer works okay for all other printed tasks it has to deal with. It just doesn't like this one.

Any ideas for this bizarre bug?

I'm going to ask a lame question, but sometimes it's best to get those out of the way.

Are there any labels that span over the top of the text?

Do you have any subreports?
If so are properties Can Grow/Can Shrink set?

I once had an issue like this, but with a Lexmark. I ended up redoing the report and adding it to the menu specifically for them because the margins had to be set a certain way in order for it to print correctly.

Strangely, there is nothing at all to indicate what may be happening.

This is an absolutely basic report. Just some boxes and printing with a short paragraph of verbage (all of it text fields).

No subreports, no shrinking or growing, nothing at all. It's just basic printing. The other four reports in this batch have those things - sub-reports, varied sized memo fields, etc. And yet they print perfectly.

Is this a great world or what?