Vista - Vista Backup won't do what I want, uses too much space

When I used to run XP, I used Arctor to back up my important folders (My Documents, Pictures, Email etc.). It used to do this automatically every night, backing up incrementally onto an external hard disk. It did this for months or years without ever filling up my 160Gb backup disk. It must have been pretty intelligent about which files to save.

When I moved to Vista, I thought I'd try the built in backup facility, but I found that after only a very few backups (supposedly incremental) my backup disk was full. What on earth is it doing with all that space? I also find it annoying that I can't control precisely which files are being backed up. I'm sure some files that I don't need are being backed up, and that some that I do need are not.

Can Vista Backup do what I want (i.e. keep incremental backups of just files I've changed or just the changes, do it automatically every night, and make efficient use of disk space)? And can I specify more precisely which files to back up?

If Vista Backup won't do this, what backup software (preferably free) do you recommend?

Thanks - Rowan