I recently acquired a vectrex console after having been looking for one for a while. Unfortunately it seems to have a few graphical issues, such as lines not meeting up in some cases and being quite wobbly on some screens, but most notably that text on the screen is sometimes 'split' and occasionally is slightly off where it should be.

Here is a picture to illustrate the problem.
http://img14.imageshack.us/img14/4699/img0997so.jpg

Some games do not suffer from this issue but others do. It always happens on the same screens and is very consistent.