Great info. And here's to not paying attention (me that is).
After redoing the whole setup several times, using syslinux but also trying grub, i just couldn't get the damn thing to boot.
My desktop has extensive BIOS so tried everything under the sky but to no avail....
Then, when dinner was on the table i left the machine to try and boot from the flash for the umpth time, it booted up hdd ubuntu, intead of knoppix dvd, and to my surprise i got 2 (TWO) usb-drive icons on my ubuntu (6.06) desktop.....that didn't show in knoppix...!!??

Opening both showed the "secret" (RTFM?) of the USB Disk Pro: I has a floppy-sized primary partition which holds a password/encryption tool to secure the second partition. Auto-format the key when 3 wrong pwds are given etc. That's why it never booted.
On XP it mounts as floppy and Removable, but i never noticed the floppy......

Time to sort out how to repartition the whole flash key.....later more on this.
Right now ubuntu mounts them as sda4 (after using mkdiskimage) 1027MB, and sdb 1MB

Edit: Think i'm screwed with this one. It appears to have firmware installed. The tool on the flash key: UDPV264.exe, i found a newer version, wich has an extra option of resizing the secure area, but trying to use that it stated Firmware not supporting option. How to get this mother to work.....to start i looks to behave as a usb-hub, ie 2 separate devices, sda and sdb.....

Sep 8 22:25:10 Acer kernel: usb 1-1: new full speed USB device using uhci_hcd and address 3
Sep 8 22:25:10 Acer kernel: usb 1-1: configuration #1 chosen from 1 choice
Sep 8 22:25:10 Acer kernel: scsi1 : SCSI emulation for USB Mass Storage devices
Sep 8 22:25:15 Acer kernel: Vendor: Model: USB DISK Pro Rev: PMAP
Sep 8 22:25:15 Acer kernel: Type: Direct-Access ANSI SCSI revision: 00
Sep 8 22:25:16 Acer kernel: SCSI device sda: 2006016 512-byte hdwr sectors (1027 MB)
Sep 8 22:25:16 Acer kernel: sda: Write Protect is off
Sep 8 22:25:16 Acer kernel: sda: assuming drive cache: write through
Sep 8 22:25:16 Acer kernel: SCSI device sda: 2006016 512-byte hdwr sectors (1027 MB)
Sep 8 22:25:16 Acer kernel: sda: Write Protect is off
Sep 8 22:25:16 Acer kernel: sda: assuming drive cache: write through
Sep 8 22:25:16 Acer kernel: sda: sda4
Sep 8 22:25:16 Acer kernel: sd 1:0:0:0: Attached scsi removable disk sda
Sep 8 22:25:16 Acer kernel: sd 1:0:0:0: Attached scsi generic sg0 type 0
Sep 8 22:25:16 Acer kernel: Vendor: Model: USB DISK Pro Rev: PMAP
Sep 8 22:25:16 Acer kernel: Type: Direct-Access ANSI SCSI revision: 00
Sep 8 22:25:16 Acer kernel: SCSI device sdb: 2880 512-byte hdwr sectors (1 MB)
Sep 8 22:25:16 Acer kernel: sdb: Write Protect is off
Sep 8 22:25:16 Acer kernel: sdb: assuming drive cache: write through
Sep 8 22:25:16 Acer kernel: SCSI device sdb: 2880 512-byte hdwr sectors (1 MB)
Sep 8 22:25:16 Acer kernel: sdb: Write Protect is off
Sep 8 22:25:16 Acer kernel: sdb: assuming drive cache: write through
Sep 8 22:25:16 Acer kernel: sdb: unknown partition table
Sep 8 22:25:16 Acer kernel: sd 1:0:0:1: Attached scsi removable disk sdb
Sep 8 22:25:16 Acer kernel: sd 1:0:0:1: Attached scsi generic sg1 type 0