"Installation failed" error when reading from GVFS SFTP mount.

[Erik B. Andersen]

USB creator for some reason cannot create a USB live disk from an image on a GVFS sftp mount.
Workaround: Copy entire file to disk, then create image from that copy.

To reproduce:
0. Put a Ubuntu disk image on a remote computer that you can log in to with SFTP.
1. Mount SFTP share from the computer that does not have the image on it.
2. With the SFTP share mounted, open USB creator.
3. Click "Other".
4. Notice that SFTP mount does not show up in sidebar of file picker. (I would expect it to show up. )
5. Right click in the files area and set Show Hidden to on.
6. Go to /home/<username>/.gvfs . Then go to the sftp mount, navigate to the file you want to use on the SFTP share. Click Open.
7. Pick any USB disk options you want.
8. Click "Make startup disk".
9. Notice error message, "Installation failed." (I would expect this to work and the disk creation to succeed.

ProblemType: Bug
DistroRelease: Ubuntu 11.04
Package: usb-creator-gtk 0.2.28.3
ProcVersionSignature: Ubuntu 2.6.38-10.46-generic 2.6.38.7
Uname: Linux 2.6.38-10-generic x86_64
NonfreeKernelModules: nvidia
Architecture: amd64
Date: Mon Sep 5 16:09:33 2011
InstallationMedia: Ubuntu 10.04 "Lucid Lynx" - Alpha amd64 (20100323)
PackageArchitecture: all
ProcEnviron:
 LANGUAGE=en
 LC_CTYPE=C
 PATH=(custom, no user)
 LANG=en_US.UTF-8
 SHELL=/bin/zsh
SourcePackage: usb-creator
UpgradeStatus: Upgraded to natty on 2011-05-03 (125 days ago)

[Launchpad Janitor (janitor)]

Status changed to 'Confirmed' because the bug affects multiple users.