wubi fails on invalid .iso on any drive

[Estee Ratus]

ubuntu 12.10

wubi silently fails when it scans all available .iso files in the root of mounted volumes.
any file named .iso which is simply a txt file renamed to .iso makes wubi crash silently.

LOG :

11-07 22:14 INFO root: === wubi 12.10 rev273 ===
11-07 22:14 DEBUG root: Logfile is c:\temp\wubi-12.10-rev273.log
11-07 22:14 DEBUG root: sys.argv = ['main.pyo', '--exefile="W:\\wubi.exe"']
11-07 22:14 DEBUG CommonBackend: data_dir=C:\Temp\pyl20.tmp\data
11-07 22:14 DEBUG WindowsBackend: 7z=C:\Temp\pyl20.tmp\bin\7z.exe
11-07 22:14 DEBUG WindowsBackend: startup_folder=C:\Documents and Settings\All Users\Start Menu\Programs\Startup
11-07 22:14 DEBUG CommonBackend: Fetching basic info...
11-07 22:14 DEBUG CommonBackend: original_exe=W:\wubi.exe
11-07 22:14 DEBUG CommonBackend: platform=win32
11-07 22:14 DEBUG CommonBackend: osname=nt
11-07 22:14 DEBUG CommonBackend: language=en_AU
11-07 22:14 DEBUG CommonBackend: encoding=cp1252
11-07 22:14 DEBUG WindowsBackend: arch=amd64
11-07 22:14 DEBUG CommonBackend: Parsing isolist=C:\Temp\pyl20.tmp\data\isolist.ini
11-07 22:14 DEBUG CommonBackend: Adding distro Edubuntu-i386
11-07 22:14 DEBUG CommonBackend: Adding distro Kubuntu-amd64
11-07 22:14 DEBUG CommonBackend: Adding distro Mythbuntu-i386
11-07 22:14 DEBUG CommonBackend: Adding distro Edubuntu-amd64
11-07 22:14 DEBUG CommonBackend: Adding distro Ubuntu-amd64
11-07 22:14 DEBUG CommonBackend: Adding distro Lubuntu-i386
11-07 22:14 DEBUG CommonBackend: Adding distro Ubuntu-i386
11-07 22:14 DEBUG CommonBackend: Adding distro Mythbuntu-amd64
11-07 22:14 DEBUG CommonBackend: Adding distro Kubuntu-i386
11-07 22:14 DEBUG CommonBackend: Adding distro Lubuntu-amd64
11-07 22:14 DEBUG WindowsBackend: Fetching host info...
11-07 22:14 DEBUG WindowsBackend: registry_key=Software\Microsoft\Windows\CurrentVersion\Uninstall\Wubi
11-07 22:14 DEBUG WindowsBackend: windows version=xp
11-07 22:14 DEBUG WindowsBackend: windows_version2=Microsoft Windows XP
11-07 22:14 DEBUG WindowsBackend: windows_sp=Service Pack 3
11-07 22:14 DEBUG WindowsBackend: windows_build=2600
11-07 22:14 DEBUG WindowsBackend: gmt=1
11-07 22:14 DEBUG WindowsBackend: country=AU
11-07 22:14 DEBUG WindowsBackend: timezone=Australia/Sydney
11-07 22:14 DEBUG WindowsBackend: windows_username=Administrator
11-07 22:14 DEBUG WindowsBackend: user_full_name=Administrator
11-07 22:14 DEBUG WindowsBackend: user_directory=C:\Documents and Settings\Administrator
11-07 22:14 DEBUG WindowsBackend: windows_language_code=1033
11-07 22:14 DEBUG WindowsBackend: windows_language=English
11-07 22:14 DEBUG WindowsBackend: processor_name=Intel(R) Core(TM)2 Duo CPU T7300 @ 2.00GHz
11-07 22:14 DEBUG WindowsBackend: bootloader=xp
11-07 22:14 DEBUG WindowsBackend: system_drive=Drive(C: hd 6806.99609375 mb free ntfs)
11-07 22:14 DEBUG WindowsBackend: drive=Drive(C: hd 6806.99609375 mb free ntfs)
11-07 22:14 DEBUG WindowsBackend: drive=Drive(D: hd 17745.90625 mb free ntfs)
11-07 22:14 DEBUG WindowsBackend: drive=Drive(P: hd 7546.01171875 mb free ntfs)
11-07 22:14 DEBUG WindowsBackend: drive=Drive(U: hd 43055.8984375 mb free ntfs)
11-07 22:14 DEBUG WindowsBackend: drive=Drive(W: cd 0.0 mb free cdfs)
11-07 22:14 DEBUG WindowsBackend: uninstaller_path=U:\ubuntu\uninstall-wubi.exe
11-07 22:14 DEBUG WindowsBackend: previous_target_dir=U:\ubuntu
11-07 22:14 DEBUG WindowsBackend: previous_distro_name=Ubuntu
11-07 22:14 DEBUG WindowsBackend: keyboard_id=-268366839
11-07 22:14 DEBUG WindowsBackend: keyboard_layout=us
11-07 22:14 DEBUG WindowsBackend: keyboard_variant=
11-07 22:14 DEBUG CommonBackend: python locale=('en_AU', 'cp1252')
11-07 22:14 DEBUG CommonBackend: locale=en_AU.UTF-8
11-07 22:14 DEBUG WindowsBackend: total_memory_mb=2038.35546875
11-07 22:14 DEBUG CommonBackend: Searching ISOs on USB devices
11-07 22:14 DEBUG Distro: checking Ubuntu ISO C:\WUBI-FAILS.txt.iso
11-07 22:14 ERROR WindowsBackend: Error executing command
>>command=C:\Temp\pyl20.tmp\bin\7z.exe l C:\WUBI-FAILS.txt.iso
>>retval=2
>>stderr=

7-Zip 9.20 Copyright (c) 1999-2010 Igor Pavlov 2010-11-18

Error: C:\WUBI-FAILS.txt.iso: Can not open file as archive

Errors: 1
>>stdout=
Traceback (most recent call last):
  File "\lib\wubi\backends\win32\backend.py", line 519, in get_iso_file_names
  File "\lib\wubi\backends\common\utils.py", line 66, in run_command
Exception: Error executing command
>>command=C:\Temp\pyl20.tmp\bin\7z.exe l C:\WUBI-FAILS.txt.iso
>>retval=2
>>stderr=

7-Zip 9.20 Copyright (c) 1999-2010 Igor Pavlov 2010-11-18

Error: C:\WUBI-FAILS.txt.iso: Can not open file as archive

Errors: 1
>>stdout=
11-07 22:14 DEBUG WindowsBackend: command >>C:\Temp\pyl20.tmp\bin\7z.exe l C:\WUBI-FAILS.txt.iso
11-07 22:14 DEBUG Distro: does not contain casper\filesystem.squashfs
11-07 22:14 DEBUG Distro: checking Ubuntu ISO C:\WUBI-FAILS.txt.iso
11-07 22:14 ERROR root: iteration over non-sequence
Traceback (most recent call last):
  File "\lib\wubi\application.py", line 57, in run
  File "\lib\wubi\backends\common\backend.py", line 190, in fetch_basic_info
  File "\lib\wubi\backends\common\backend.py", line 803, in find_any_iso
  File "\lib\wubi\backends\common\distro.py", line 113, in is_valid_iso
TypeError: iteration over non-sequence