Macduff is in trouble with Macbeth because he has failed to appear to a political and social function to which Macbeth has invited him.  Further, Macduff has acted strangely toward Macbeth ever since Macbeth was named Duncan's successor to the throne (after Duncan's death and Malcolm's flight).  Though Macduff is a Scottish lord and therefore should have attended Macbeth's coronation at Scone, he chose, instead, to go home to Fife at the end of Act II, scene iv. 

Now that he's ignored Macbeth's explicit invitation to his home, he has slighted the king too many times to go unnoticed or unpunished in Macbeth's eyes.  After all the guests have left, Macbeth asks his wife, "How say'st thou that Macduff denies his person / At our great bidding?" (3.4.159-160).  It is inappropriate for Macduff to have repeatedly denied his presence when it is either expected or requested by his king, and Macbeth can no longer assume that it is an oversight or accident when he has expressly "bid" Macduff to come to him.