I've found this happen a few times over the last month or so. I'm not sure when it started happening to be sure, it may have been 1.17. But allow me to explain;

While playing FFXIV WINDOWED I Alt-Tab often and talk on MSN, Browse and whatever else.
An issue has arose recently where upon Alt-Tabbing back to FFXIV the game window will not respond to keyboard input, mouse input. Even with clicking the X in the top right; which causes the confirm box to come up; "YES" or "NO" cannot be clicked.

Anyone else have this issue?

Thanks