linux - Difficulty getting Universal USB Installer to work in WINE

I have a 16GB USB flash drive inserted into a machine running Linux Mint.

I want to use the Windows program Universal USB Installer via WINE (the end goal here is to create a XenServer bootable USB drive as described here, but that's not relevant to this question).

Currently this is the status of my USB flash drive with fdisk:

# fdisk -l /dev/sdb
Disk /dev/sdb: 16.0 GB, 16008609792 bytes
64 heads, 32 sectors/track, 15267 cylinders, total 31266816 sectors
Units = sectors of 1 * 512 = 512 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes
Disk identifier: 0x000e2ab6
   Device Boot      Start         End      Blocks   Id  System
/dev/sdb1            2048    31266815    15632384    b  W95 FAT32

So everything appears to be fine, but when I load up Universal USB Installer with WINE, it doesn't detect my USB drive:

I edited the image to remove the username, but as you can see, the USB drive is not shown.

So I ran wincfg to see if I can manually assign the drive...

^{(The image has been edited to remove the user's name.)}

It looks like WINE is successfully detecting my USB drive (the /media/$USER/87F1-4491), so why doesn't Universal USB Installer see my USB device?

Also: I know that a bootable USB can simply be made using dd; however, for some reason which is currently beyond my understanding, this doesn't seem to actually work in practice with the XenServer ISO. This seems to be a known issue, as the XenServer blog specifically recommends using Universal USB Installer. I tried using dd with the XenServer ISO, and it doesn't boot. (I have used dd many times with other bootable ISO files successfully, but for some mysterious reason it doesn't work for XenServer.)