So...
1. Installed 2012 from scratch, promoted to DC, other roles are DNS obviously and DHCP.
2. Installed Windows 7 on several PC's and joined to domain in computers container.
3. Created 1 User in a new OU and attached an empty Policy, then created a folder redirect for the desktop.
4. Typed username & password in all machines and ran round and pressed enter, all log on in order quickly.
5. Added .txt file to desktop and repeated step 4, all log on in order quickly.
6. Added .lnk file to desktop and repeated step 4, 1st one logs on fast all others are delayed for around 35/40 seconds then logs on simultaneously. ***
7. Kept both .txt and .lnk file on desktop, logged on the 1st one, waited 1 minuet before quickly logging on the rest, the others then log on fast and in order.
Seems to be an issue with the 1st Machine locking the .lnk file for a while. It doesn't matter if the .lnk points to a local folder or .exe or a UNC or Drive letter, even pointing to an I.P.
If I add a second 2012 server as a file server and redirect desktop to this machine and repeat steps 4-7, there are no issues at all.
This also occurs when you redirect start menu/favourites etc.. as well.