I have a cheap Denver dvd player.
Some weeks back my gf watched an anime series on DVD and she pointed out a very obvious problem with the image on the screen; in almost every scene there was something rather odd happening to the cartoon outlines, you can call it aliasing or pixelation or whatever.
I tried playing it on my computer and although still not perfectly smooth, it looked 90% better.
Last night I watched Shrek 2 and in some scenes I noticed the same thing, characters' and shapes' edges were shown a bit "stepped", aliased you might say. although not as distinct and it didn't disturb the movie that much.
I haven't noticed this at all with typical filmed movies, maybe because there are no strong, sharp lines and shapes such as 2D/3D cartoons have.

could this be an "interpolation" problem? I'm not exactly sure what it even means technically but I'm guessing that's what it could be called?

So my main concern is:
a) Should I buy a new dvd player? AND b) How can I make sure the new one is any better?

thanks in advance!

EDIT: oops, sorry for posting in the wrong section

It's called "Stairstepping" and is caused by the relatively low dot pitch (resolution) of TV's and interlacing, it's more evident in cartoons because of the dark outlines.
In the follwing example lines 1&3 are drawn on the first pass of the electron gun in the TV and lines 2&4 in the second,

Because you can see the gaps between the lines AND interlacing draws the eye and makes it MORE evident still, it appears to be very jagged, unless some form of edge enhancement / anti-aliasing is done on the DVD there's not much you can do about it. You could try playing with the sharpness options on your TV and DVD player if they have them. The only other option it is with a DVD player such as the Denon DVD-A1XV (currently ~?2750!) which has a Multi-directional diagonal filter to address that very issue.
The PC upscales and interpolates the image to whatever resolution you are currently running at and draws the whole lot in one pass makeing it less noticeable. Drop your PC resolution to 720*576 (PAL resolution) and it'll be more evident there as well, although not as much as the TV as the dot pitch of a monitor is FAR greater.

[edit] Moved to FAQ section.
Plus, Am I right in thinking it affects low-angle Diagonals more than higher angle ones? (i.e angles ~30degress or less)[/edit]