915 resolution does work on VL.. I've used it before. Not sure if it can do your particular resolution, but normally you'll need to isntall it and do some testing ... This is best done from cli
915resolution -l
will get you a list of the supported modes
You'd pick one that's not being used and patch it with you resolution
915resolution xx 1440 900 24
where xx = the mode you picked from the list (ie 5d, 4a, etc)
You'd also need to set your /etc/X11/xorg.conf to use that resolution with a 24bit depth
Start X and see if it's right
If it fails, pick another mode from the list and use the same values until it works
When you finally get the one that works, make sure you remember wich mode worked and you'll need to add that to your /etc/rc.d/rc.local to make sure it looks good every time you boot
The manual says to add it as the last line in the file, but I've found that if you do that, sometimes it does not work... so I'd add it right after the
#!/bin/bash
line to make sure it does get patched.
your line should look like this
/absolute/path/to/915resolution xx 1440 900 24
HTH.