ackk - 4:55 pm on Nov 10, 2011 (gmt 0)
We've had tons of pages noindexed for 6-7 months. Many of them still appear in Google's index.
The only thing you may want to check is to make sure that the noindexed pages are accessible. If the crawler can't access the page in the first place, it won't know that the noindex tag has been added.