Cant find Correct 1024x768 1:3 values

[Pangaea]

hi folks
im working on a project, and all the images must be 1024x768 and in 1:3 quality
I cant seem to get m3d to set the correct aspect value for 1:3 .. for some odd reason also its jumping from 1:2 and 1:4 .. im not sure if this is a bug, but can someone tell me the correct resolution to output images in 1024x768 at 1:3 so i can enter it in manually

hope someone can help
regards

[Pangaea]

igh.. sorry wasnt thinking.. just did the math

tho it is still jumping from 1:2 to 1:4 , but that wont have any baring on my work