I have various machines running Intel Gigabit NIC (both onboard, server dual-port pci-e, and desktop single port pci-e). They all run on either Vista x64 or Server 2008 x64. Installing Proset (13.1/13.3/13.4) on these machines takes a really long time (upwards of 45mins!). During the time, the machines will seem to have hung at the setup screen with network disconnected. And sometimes the install fails.
Also, once the Intel proset is installed, activating adapter teaming on server 2008 machines (only tried it on the server) in AFT/ALB modes, the system will suffer BSOD due to TCPIP.SYS. However, without iANS teaming, server is rock solid. It takes ages to change settings for the NICs via the device driver pages as well (on both server and other desktops, onboard/pci-e).
These behaviours does not existing with other manufacturer's NICs on those same machines....
I haven't seen any kind of delay like that. Possibly interfering with some other application that gets preinstalled?
Have you tried installing 14.5 as the first package after the OS install (assuming you don't have other bundled components slipstreamed in)