Hugo Jonker <hugo(at)gewis(dot)win(dot)tue(dot)nl> writes:
> Upon doing a faulty INSERT which left a column with default value
> nextval('sequence') unspecified, the INSERT aborted due to an error.
> However, a call had been placed to nextval('sequence'), thus
> increasing the sequence, while this value never got used.
> I certainly didn't expect this.
Then you didn't read the documentation. Sorry, this is not a bug.
regards, tom lane