Got a X51v yesterday for work. Actually ordered a X50v but Dell said that they are not shipping those any more. In any case, most of the software I need to use here is incompatible with Mobile 5. And the majority of the softwares I had for my previous PDA are not useable. Can you install 2003 se into a X51v sucessfully (I know that there is a rollback utility to move from Mobile 5 to SE on the X50v on the Dell website)or is there a 2003 SE emulator I coud run on my new machine?

If there is a way to do it, it probably isn't legal.

Also, the X51 doesn't have a backup battery, so you wouldn't be able to rely on that to save you if your main battery dies.
I am not sure how the small amount of RAM would effect using WM 2003.
Though, I think many devices only have 64 MB of RAM, I am not sure.
My iPAQ 5555 had 128 MB of RAM.

 

from reading both here and the dell forums, I would have to say that you cannot downgrade an X51(v) to Mobile 2003SE.

I'm sure that there are people trying to, but for the time being, I would say that it's not possible. Check with the vendors of the programs you need. A lot of them are adding support for WM5.0 rather quickly, and it may surprise you to find that you actually have software that is compatible in a matter of a few short weeks.

As for me, though, I'm back on 2003SE on an X50 mid because WM5.0 causes too many problems ><