The Saw films have demonstrated an unfeasibly high success rate over time in terms of pulling off twist after twist and having them nearly all hit home.
With this track record, it seems inevitable that there’d be a significant stumble at some point.
They’ve never been bulletproof films (and thrillers are the genre that are hardest to bulletproof), but I’d say Saw V is definitely the stumble.
In spite of this, it still keeps in enough with the series in general for me to be ready for Saw VI in 2009 – which I hope will be better work. 
Following Jigsaw’s grizzly demise, Mark Hoffman, the final apprentice to the serial killer is reigned a hero.
Agent Strahm is tested and puts the pieces together, Strahm realizes that Hoffman is helping Jigsaw, five seemingly unconnected people face a horrible lesson of teamwork.
enjoy! 
magic
Warning:- this post does not contain the films Goofs.
… now for Magic’s Technical Bit:
Director
David Hackl
Writers
Patrick Melton
Marcus Dunstan
Release Date
24 October 2008 (UK)Â
Genre
Action | Crime | Horror | Mystery | ThrillerÂ
Tagline
You won’t believe how it ends.
Plot
Detective Hoffman and Agent Strahm clash as they each investigate the apparent continuation of the Jigsaw murders.