Guarded optimism for 49ers' offense

  The team had something very close to a complete-team effort in yesterday's 35-0 victory over the Rams. But the offensive line did not perform up to expectations. Coach Mike Singletary said he plans to sit down with offensive line coach Chris Foerster to kick around some ideas for kicking that unit into gear.   It's pretty clear where the problems originated on Sunday in the 49ers' 35-0 victory over the Rams. Singletary said left tackle Joe Staley is continuing to mature. He said Eric Heitmann is working his tail off. He said the right-tackle combination of Adam Snyder and Tony Pashos did a good job.   Uh-oh. He did not heap any praise on guards Chilo Rachal or David Baas.   "They did not play up to par," Singletary said. "I know that whatever it is, we'll just have to figure it out. Baas still could be banged up a little bit, I just don't know. We'll get to the bottom of it and figure out what it is, because both of those guys . . . w...