i have two monitors, and whenever I move a window from one monitor to the other it will kind of lag/snap when the cursor hits the edge. This only happens if I don't move the window really really fast. Does anyone else recognise this issue and know any solution? It's really annoying.

Quick tiling?
run "kcmshell4 kwinscreenedges" (assuming this is KDE4) and uncheck "Tile windows by dragging them to the side of the screen"

Sorry for the late reply. I had installed a distro called Bridge, which is based on Arch. It was a year old, and I didn't see that there was a newer version out. After I didn't pay enough attention to what packages I was upgrading I effectively broke X. I tried fixing it, but gave up. Then I saw that the new version of bridge was out, so I installed it. Since then I've not had the snapping problem. It must either have been an old version of KDE (very likely) or a graphics card driver issue (also very likely).