Hi keyi, there is an option in the importOBJ script to not normalize the object like it does by default.

There's some information here on the setting:
http://moi3d.com/forum/index.php?webtag=MOI&msg=6674.201

To use it, modify your keyboard shortcut to give the parameter "exact", by adding it to the end of the shortcut separated by a space, so your shortcut should read like this:

_ImportObj exact

Also make sure you're running the latest one which you can find on Max's file archive here:
http://moi.maxsm.net/media/files/

- Michael