I suspect a power issue.
To connect it right: from left to riht: Ground, +5v supply, DQ (1-wire)
Even with only gnd & dq, the led will lightly light on, but the chip will not be enough powered.
Do you use a separate power supply or power from usb? via a usb hub? powered?
Could you double check the presence of 5v from your cable ? 
When connecting only gnd and +5v could you verify that led turn on, if you have a multimeter, measure the voltage on the screws.
When tinyboard is connected, are other devices showing up?

Could you connect the tinyboard only, then report the dmesg at moment you connect the ds9490?
you should see something like this:
[ 2430.256057] usb 2-2: new full speed USB device using uhci_hcd and address 2
[ 2430.481088] usb 2-2: configuration #1 chosen from 1 choice
[ 2430.559165] Driver for 1-wire Dallas network protocol.
[ 2430.573393] usbcore: registered new interface driver DS9490R
[ 2432.167097] w1_master_driver w1_bus_master1: Family fc for fc.990000000000.cc is not registered.
confirms ?

on owfs side, connect only the tinyboard and capture the output when starting your ow daemon with:
/opt/owfs/bin/owhttpd -u -p 81 --foreground --errorlevel 1
do you see this?
CONNECT: ow_ds9490.c:USB_next(623) Bus master found: 002/002
DEFAULT: ow_ds9490.c:DS9490_sub_open(555) Opened USB DS9490 bus master at 002/002.
DEFAULT: ow_ds9490.c:DS9490_detect_found(437) Set DS9490 002/002 unique id to FC 00 00 00 00 00 99 CC
CONNECT: ow_ds9490.c:DS9490_detect_low(336) USB DS9490 1/1 successful bound

Pascal