Built and captured new wim and included all updates but more updates get applied when I build from that wim

Question

EDIT: This is on SCCM 2012 R2 CU3
(EDIT: simplified title)
I have a task sequence for building reference images from. This runs the Software Updates Step last and seems to work fine. When it completes I reboot the target machine then do a capture to wim (using the SCCM capture iso).
I import the new wim and link it to the GOLD build task sequence, but when I build from from it the machine tries to install another bunch of updates.
The OS I'm building is 2008 R2 SP1. I have all updates from year 2008 deployed to the right collection.
Why does it try to install more updates??
I was considering using SCCM to install the updates directly into the WIM but I'm no longer convinced it will work. I just want a gold image, built from scratch, with all updates in it.
Andy

Answer 1

P1: Agreed. I didn't do a very good job of explaining myself.
I have failed to get the multiple "install updates" methods to work at all, though I would love it to work. For Server 2008 installs the process gets stuck for 20mins on the "Detecting Updates..." stage, and loops round again to download
the same set of updates it did the previous time never reboots, and gets stuck at "Detecting Updates" again. For server 2012 installs it seems to work but it never get all the updates, even after 5 loops of the install updates step.
I've read sp many posts saying they've got the multiple "install updates" method to work fine. I've tried building my Task Sequence to be exactly as posted by several different people. I've also tried my own improvements. The result is the
same every time, so I don't think there is a problem with the TS.
Thanks for you feed back. It is useful to know it "can" work as it implies there is a problem someone (either with me or SCCM). You help is appreciated.
Thanks.
As a side note, I'm going to make a new post for the following. I did a bit of further digging and it seems like this might be related to why the above is not working....
I've built a 2012 and a 2008 server with a single "install updates" step in the task sequence. When the build is finished I then run windows updates within the OS. The result is "No More Updates Found", I felt this was suspicions
as there were no were near enough updates installed already. I then pointed the machines at Microsoft's update servers and, bingo, it finds more updates. I assumed these updates where missing from my Updates Package in SCCM but that turned out to
be wrong, they are right there, distributed to the DP, and deployed to the right collection.
As far as I understand it, you don't need to touch the WSUS console, but seeing as I didn't build this SCCM environment, I thought I would check it out anyway. It looks like WSUS may have been partly configured directly at some point, rather letting
SCCM to it all. Example: I searched in the WSUS console for appoved updates and found 6 old ones (2003 server and XP) approved for Install. A further search found 421 "Declined" updates. Everything else is marked "Not Approved".
Does any of this matter if SCCM is supposed to be managing it? Should I trash WSUS and the SCUP and reinstall it, or is there something else I should be doing?