Grid view. Unmatched bets window floating. Other bet windows docked.

If I place an SP bet first (which goes in unmatched SP bets window) and then place a normal bet (persistency irrelevant) (goes in unmatched bets window) the Unmatched bets window starts flashing and bet placement/editing is hindered.

Only way to stop it is to close and reload market. It will restart doing it if I repeat the sequence.

Any thoughts on what is going on here and if there is a fix (other than docking the window)?