Just done an oil change today and consulted the Haynes manual for the sump plug and filter torque settings. It didn't mention the filter, but it said the sump plug should be torqued up to 23nm. So that's what I did.
Now, on removing the filter housing and cleaning it up ready for refit, I noticed that it had, printed on it, the torque settings for it, and the sump plug. It said that the sump plug should be 10-11nm - less than half of what Haynes said.
I've left it at 23nm because even that didn't feel massively tight, and I'm sure thats what I did it to the last time.
Which is right?