Simsi - 4:27 pm on Sep 18, 2010 (gmt 0)
I did this on a site in February. Only 25 pages but added auto-linking back to the homepageon each one. On March the 5th the site's homepage got a -950, returning exactly 6 months to the day. I can't be sure it was that as I did two other changes at the same time but they were more minor and I regressed them all in April to be safe.
However, I think if the links come in at the same time as the page itself and aren't overdone - ie: done for the user or as footer links - it would be ok.