I had a look through the threads and couldn't see anything that sounded the same as the problem I'm having, so hopefully this hasn't already been addressed (and apologies if it has).
Every 20 minutes or so of playing the game I will get this weird graphics blur anytime I try and scroll the screen. Everything on screen kind of sticks in place and blurs if I try and scroll, but things moving of their own accord (guards on patrol, etc) will walk through the bluriness just fine.
I haven't been able to figure out what causes it, and the only way to fix it that I've come across is to save the game, quit back to windows and restart (which is annoying considering the 3 small vids you have to skip and the load time)
I just noticed seen people talking about adding -no3d -doublebuffer to the shortcut for some other graphics issues, so I'm going to try that when I have a chance (that'll be a couple of day though as I'm in the middle of moving house).
Any help in the meantime would be great.

Those 2 switches worked like a charm.
Now I'm thinking that someone from GOG might want to edit the Arcanum installer so that the shortcuts that are generated already have those switches included. I don't know exactly what they do, or why they work, but they seem to fix a number of different issues people have, and I can't see what downfall there could be to using them even if you didn't need them.

Glad to hear they worked for you, the switches usually clear up graphics problems.
Here is a link to the Arcanum command line arguments if you would like to see what they do. I have not heard of any negatives from using the switches, the worst might be lowering the graphics quality somewhat with the -no3d switch. I can tell no difference with or without the switches and my install seems to run either way so I just leave them both . . . =)

Hate to sound completely stupid, but how can I add those to the target in Windows 7?

Right-click on the quick launch icon on your desktop. Click on Properties. Edit the Target field in the Shortcut tab.

Ah, it has to be a desktop shortcut. I've been using it from my taskbar. Thanks!