Don't take eggs this time until you're sure she's been completely ignoring nest for at least a week (keep a count of eggs - no more added to total for 7 days and absolute indifference to nest on her part).
Something might have been stressing her/locaion of nest might be somewhow unacceptable.
How many years has this been going on? How many eggs are in the nest when she `gives up'? Does the tom have access to nesting area? What do you use for a nest?