I'm trying to do a full reflash of an N900 from a 32-bit Ubuntu laptop.
I'm trying to get flasher-3.5 to download the firmware, by doing the following steps:

1) Remove the N900 battery to make certain it is off.
2) Re-instert the battery (it does not boot at this point).
3) On the laptop, run

sudo flasher-3.5 -F RX-51_2009SE_1.2009.41-1.VANILLA_PR_EMMC_MR0_ARM.bin -f

That command immediately produces the following output:

Image 'mmc', size 241163 kB
Version RX-51_2009SE_1.2009.41-1.VANILLA
Suitable USB device not found, waiting.


4) While holding down the "u" key, I plug the USB cable into the N900, the N900 powers-up, dispalys NOKIA with no backlight, and shows the USB icon. On the laptop, the following text appears:

USB device found found at bus 002, device address 009.
Found device RX-51, hardware revision 2104
NOLO version 1.4.14
Version of 'sw-release': RX-51_2009SE_21.2011.38-1_PR_MR0
Booting device into flash mode.
Suitable USB device not found, waiting.


The USB icon on the N900 disappears, but nothing else happens. In particular the firmware does not download.
The front LED on the N900 illuminates amber continuously.

I have also tried executing "flasher-3.5 -i", just to check that USB comunications are taking place. The command produces the following output:

USB device found found at bus 002, device address 005.
Found device RX-51, hardware revision 2104
NOLO version 1.4.14
Version of 'sw-release': RX-51_2009SE_21.2011.38-1_PR_MR0


DOes anyone know what might be going wrong here? The laptop is clearly communicating with the N900 to some extent, because the outputs quoted above appear immediately after the USB cable is connected to the N900. But for some reason, flasher-3.5 is just refusing to proceed with the download.

Thanks for any tips!