Red highlighted squares?

I was playing a 30 min game a few minutes ago, and was about three minutes ahead of my opponent (~8 mins vs 5 or 6mins). As I was going to play my next move, the square of origin for the pawn and the destination turned red and the game did not record my move, and I eventually lost on a time forfeit because I couldn't move. I'm not sure if this was an issue of lag, considering my connection was just fine and my opponent's lag was pretty horrible. If anyone has any thoughts or possible suggestions, please let me know. Thank you.

[Sansen]

Hi,

You might have encountered a bug. This thread might give you more info: viewtopic.php?f=12&t=1571

On a side-note; Are you aware of pre-moves? defaultly it is noted with a highlighted "red" color as u explained. Maybe you didn't notice that you made the move. Could you locate the game you played from your game history?

-Sansen