Its set to a 5 minute update (top 10 posters) but its been 15 minutes since I posted, the count was 2 behind.
However as soon as I forced always build my count went up by two and equals the true count.
I know it is cached, I saw this as the post count in top 10 jumped each refresh, but it goes up to the actual count less two.
But as its a portal use, it should not have to be forced to always build?
This is why I thought it was a bug... My co-admin noticed the same thing..