i hope this is not a duplication. i lost the message after "previewing" and then clicking on the "back" arrow. at least, that is what i thought i did.
pressing the "home" key while the search text is highlighted after searching UP causes the insertion point to move to any one of the 3 usual positions: beginning of the line, top of the page, top of the document.
what appears to be happening is that the "home" target does not get reset by a search up. pressing "home" 3 times with intervening searches (up) causes the insertion point to move to 1) beginning of the line, 2) top of the page, 3) top of the document.
dehighlighting, by pressing the left arrow, leads to normal behavior, namely, pressing "home" causes the insertion point to move to the beginning of the line.