Focusrite Scarlett 8i6 issues with Cubase

I have just bought a Focusrite Scarlett 8i6 USB 2.0 audio interface to replace an aeging M-audio Delta 44 (whose i/o box is getting past it).
Initially (even with their latest drivers) I had tremendous USB disconnection issues until I moved to a different USB port (away from the Steinberg dongle key). With that seemingly solved I opened Cubase 6 only to find very bad latency issues. I switched back to the M-audio and also a Guitar Rig Kontrol 2 USB interface and both had almost innaudible latency when monitring an input through Cubase. I switch back to the 8i6, but I hear something like 250-500mS of delay in the monitored signal despite the 8i6 showing about the same latency as the M-audio in the devices setup screen.
I ran up guitar rig with the 8i6 and got very low latency in the audio.
I know I can use direct monitoring with the 8i6, but it is nice to run guitar through some FX whilst recording, which I never had an issue with on the older hardware. I just can’t work out why it only seems to be an issue when running Cubase.
Just wondered if anyone lese had seen this or had any pointers

PC i5 core (can’t remember the speed off the top of my head
Windows 7 Home 32-bit

PC is reasonably well optimised for audio, well no real issues with the other interfaces anyway.