Viewport rendering split

[Nick_Reid]

Does anyone know why some rendered viewports appear with a vertical dislocation or slight difference in vertical scale at the centre. I am trying to produce final quality renderings of elevations and renderworks keeps producing a vertical split dislocation in some views. This is on the PC version of VW11 architect with renderworks and the problem occurs with textured renderings, either OpenGL or Renderworks. It can sometimes be allieviated by changing the viewport crop or rendering on a different sheet layer and then copy/paste to the final artwork layer. I should also add that The PC uses an AMD XP3000 processor and has a GForce 5200 256Mb graphics card. Changing the card does not cure the glitch and it also happens on the Mac Version (G4/533DP/1GB- 10.3.6)

Any suggestions would be much appreciated.