Ivan,
You need to email:
techsupport@irextechnologies.com and CC:
info@irextechnologies.com
The major problem is that you need the proper paperwork to send the unit back to Germany. They generally email that to you and then send you a box to send the unit back in. The box is supposed to come with a pre-paid UPS return label.
The brown return box is the exact same box they ship the iLiad in. If you saved yours, you have the brown box. The white box inside the brown box is the white box inside the black iLiad retail box. If you saved your black iLiad retail box: you have the white box.
If you can convince iRex to just email you the customs paperwork and the UPS account number, you can save a couple weeks by not waiting for a return shipping box.
Or you can do what I did and just pay for the return shipping yourself to save time.
I've done it all three ways now and I can tell you, waiting a couple weeks for the return box and then getting no return label really can lead to anger.