Go to symbol under cursor (F2) or context help (F1) often works only after the 2nd call

The problem arises from time to time:
1. Put the mouse cursor to some symbol, press F2 - sometimes it opens not the correct place, just the correct file, but places the cursor at the very different position.
2. Put the mouse cursor to some symbol, press F1 - often the correct help topic appears only after the 2nd press, the 1st press opens the incorrect help topic.