I sometimes get a similar message using FireFox (I get the message about resending data, not the bit about billing) and wondered why. It seems to happen on the Search tab more than anything else and I'm not using the shortcut to refresh but simply using the refresh button on the browser.
I have no clue why but would be nice if it stopped.
The "R" shortcut is the same as pressing the refresh button. It does a full refresh of the entire page, which can cause some of the current state to get change back to the default. Also, if any edits have not completed, they might not finish saving. A quicker way to refresh the list is to click the tab that you are already on.