Soo, one way to solve this problem is to patch your ET to 2.60. Its the most easy way, but at last its your decision ,
A other way is to create your own autoexec.cfg therefore you have to open word or a new textdocument and put into this autoexec: seta r_mode "6"
You ve to save it as "autoexec.cfg" and put it into your /etmain
The particular Graphic solutions which u ve to write into your autoexec. are:

A Display-Solution of 960 x 720:
seta r_mode "5"

A Display-Solution of 1024 x 768:
seta r_mode "6"

A Display-Solution of 1152 x 864:
seta r_mode "7"

A Display-Solution of 1280 x 1024:
seta r_mode "8"

A Display-Solution of 1600 x 1200 :
seta r_mode "9"

seta r_mode "10" doesnt exist for ET and is not a supported resolution