I have a layout that contains 33,466 records. But when I do a tab-delimited export and open in Excel, I get 33,491 records. Not only are there more records than in the source of the export, but some of the records that are in the source are missing from the export! (But represented by blank rows.) I traced it down to records that don't have a corresponding record in a related table. (But then I removed that relationship and it did not make any difference.)

Call me a purist, but if I'm looking at a found set of x records and I do an export, I expect to see x records in the export, with no additions or subtractions! In this case, it looks like there are additions AND subtractions.

Any solutions?

Not to nitpick, maybe this is part of the problem:

"I have a layout that contains 33,466 records."

Should be, "I am viewing a layout that has a found set of 33,466 records." Tables have records, not layouts.

This is quite hard to troubleshoot from afar. There might be something to the "related records" part of this that is causing the discrepancy. Are there any repeating fields? Maybe if you upload the file, or a screen shot of the relevant part of the relationship graph and the export mapping dialog...

Do some testing: save the export file in Excel format (and other formats) and see whether the row count changes.

Excel does some weird things with data without prompting and without the ability to reverse them (like assuming fields contain dates). It may be that some fields contain tab or carriage return characters and this is confusing things.

Also try opening the files in a text editor, NOT in Excel, and see what's going on.