Last season we conceded 2 or more goals in a league game on only 8 occasions and had the joint best defensive record in the division. Half of those occasions were in a dreadful 6 game spell in December/January, meaning that over the remaining 40 games (split 19 before that run/21 after that run), we conceded 2 or more on only 4 occasions.
This season we've conceded 2 or more in 7 of our 10 league games.
Last season we won 4 points from our 8 games when conceding 2 or more. One was a last-gasp leveller at Reading while we were battering Birmingham City out of sight until they pulled 2 goals back.
I agree totally about the sloppy nature of some of our goals. This wasn't anywhere near as evident last season. Maybe it's the increased pressure of playing in the top division - if you know a mistake is going to be punished far more often, you are under more pressure not to make a mistake, which can increase the likelihood of a mistake. There's also the issue of conceding too much possession, though we've been better with the ball ourselves this season.
I also think it's because our defence is better suited to the rough and tumble of the Championship, where pace and trickery are in much shorter supply. They've earned the right to be our bedrock in the Premier League, but if mistakes can't be stopped, then we need Vinny to open his cheque book.