Dave,
The " Go to first unread post" link on each thread seems to be hit and miss for me.

Click it sometimes and it takes me to the last post in the thread, even if there were 4 or 5 above it i haven't read yet.
and sometimes it takes me to the first one i haven't read yet.

I.E.
this thread here, i clicked it and it worked correctly.

My thread " To Quad or Not to Quad" took me to the last post, but there were about 7 or so i hadn't read yet after i was gone last week.

g-man