isopath and dimagepath don't work with relative paths

looking at a Wubi log, it looks like Quotes are used ie --isopath="Downloads\oneiric.iso"

How about adding a "Specify you own disk..."at the bottom of the Desktop Environmet ComboBox? so the user can point to it there instead of having to do a commandline argument?

Also how about adding to that list as it does in Wubi internals ie:
Xubuntu-i386
Xubuntu-amd64
Kubuntu-amd64
Mythbuntu-i386
Ubuntu-amd64
Ubuntu-i386
Mythbuntu-amd64
Kubuntu-i386

though call the amd64 '64-bit' and i386 '32-bit' for layman ease :)

so the 'Desktop Environment' combobox list could look like:
Ubuntu 32-bit
Ubuntu 64-bit
Kubuntu 32-bit
Kubuntu 64-bit
Mythbuntu 32-bit
Mythbuntu 64-bit
Xubuntu 32-bit
Xubuntu 64-bit
Specify you own disk...

if Wubi detects the system as 64-bit, it would set the combobox selected index as 1 (Ubuntu 64-bit), otherwise specify 0 (Ubuntu- 32-bit)

How about also adding any detected local ISOs and images - adding if they were verified with metalink and MD5 or not. The User could then choose to use the iso/image even if it fails to verify :)
something like Ubuntu 11.10 Beta 2 32-bit iso - Verified, or Ubuntu 11.10 Beta 20111003 32-bit - Unverified

The reason I say about the ability to use an unverified disk is the user may know the image is fine, but say there is no internet access - a proper offline install where Wubi cannot verify it for instance, or the server wubi checks happens to be offline, which would give the 404 error.

Using CommandLine Arguments before kicking up a GUI kinda negates the point of a Graphical User Interface somewhat :)

Hope this helps development of Wubi! keep up the great work guys!!!
-SRved