hd-media iso-scan finds usable iso's but still fails, modprobe: invalid option -- 'l'

[Sander Eikelenboom <linux@eikelenboom.it>]

Hi all,

I'm trying to get a multiboot USB stick working with a Debian installer.
I downloaded the wheezy hd-media vmlinuz and initrd.gz and 
debian-7.5.0-i386-netinst.iso. 

Configured syslinux:

label debian_wheezy_i386 debian_wheezy_hd_media
        menu label Debian Wheezy i386 debian_wheezy_hd_media
        KERNEL /debian_wheezy_hd_media/vmlinuz noprompt
        APPEND initrd=/debian_wheezy_hd_media/initrd.gz

Everything boots fine and the first steps work fine, however:

The step "scan hard drives for an installer ISO image" fails.

So i opened a shell and took a look at /var/log/syslog, and to my surprise:

Jun 25 08:55:04 kernel: [   13.743081] FAT-fs (sdb1): utf8 is not a recommended IO charset for FAT filesystems, filesystem will be case sensitive!
Jun 25 08:55:04 iso-scan: Mounted /dev/sdb1 for first pass
Jun 25 08:55:04 iso-scan: Found ISO ./debian-7.5.0-i386-netinst.iso on /dev/sdb1
Jun 25 08:55:04 kernel: [   13.874590] ISO 9660 Extensions: Microsoft Joliet Level 3
Jun 25 08:55:04 kernel: [   13.878239] ISO 9660 Extensions: RRIP_1991A
Jun 25 08:55:04 iso-scan: Detected ISO with 'stable' (wheezy) distribution
Jun 25 08:55:04 iso-scan: Detected ISO with distribution 'stable' (wheezy)
Jun 25 08:55:04 iso-scan: Debian ISO ./debian-7.5.0-i386-netinst.iso usable
Jun 25 08:55:04 main-menu[294]: (process:1325): modprobe: invalid option -- 'l'
Jun 25 08:55:04 main-menu[294]: WARNING **: Configuring 'iso-scan' failed with error code 1
Jun 25 08:55:04 main-menu[294]: WARNING **: Menu item 'iso-scan' failed.

It has mounted the usbstick on /hd-media and has found the iso and deems it 
usable !

The strange thing is the "main-menu[294]: (process:1325): modprobe: invalid 
option -- 'l'", googling on that didn't turn up much useful.

I also tried the hd-media installers for testing and sid with the same result.

Does any of you have an idea what goes wrong (or how to find out) ?

Additional logs and info attached.

--
Sander

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