Hi there,
This is unfortunate news. I have an asus g51jx-x3 and have not been able to get my external eSATA enclosure (rosewill rsv-s8 w/ sil3762 port multiplier) working. Like you it only recognizes a single drive. Is the w90 the only model that will work? I was under the impression that the chipset in my g51jx-x3 (intel 3400) supports port multiplying. How did you contact the asus support to get your answer, I would like to obtain some more information and perhaps sell my laptop for something else if this ability isn't an option...
thanks!
zephyr