That's possible, and encountered quite often. In case of intensive current draw, your hub would just "faint" due to low power, silently. The plus side, is that you can enumerate, and as responsible user, you add external power to y-cable power branch, before starting to use network heavily. In many times, lack of idiot-proof safeguards in hardware can be very helpful

I'm really glad, that you've got it working. BTW, if someone thinks that we're "screwed" due to our 200mA limitation and hostmode implementation - some android tablets were so painfully screwed hardware-wise, that they can't provide *any* power at all, while still capable of hostmoding when correctly hacked kernel gets loaded - it means that they need voodoo'ing with attaching external power to enumerate *anything*, including things like ensuring that power comes to the device to power it up and start enumerating process, but not to the whole line and host, as it would prevent enumerating... (setup based on diodes).

/Estel