Sorry to hijack like this, but i had the same problem with my E7. It wont charge using iphone power adapter. Reason i want to use it is because i've replaced the usb connector inside my E7 and it seems it only charges with usb-PC cable, so i want to use that with my phone. And only way i can connect to mains is by using this adapter.
I took the adapter open and noticed it had the data+/- bridged and had voltage going to them through a resistor. I tried removing the resistor so data lines are bridged but still no go.. I tried unbridging them but still wouldn't work.
Does the E7 need different pinout for making it work with a charger?
I have a converter that works in a car socket, and that works fine with this cable. I measured the pins on that, and it seems to get about 2.7volts on the data pins, so maybe i need to connect lower voltage for data pins?
Thanks for any help..

Why didn't you bother to read the previous posts?

n900 requires a standard usb charger, where D+ and D- are connected to each other and may/should be left floating together.

Apple chargers are NON-STANDARD and have D+ and D- at certain voltages using a resistor network.

Yes, i did. But did you read mine? I was asking how could i make this charger work with E7?
I already tried connecting the D+/- together floating separately, by changing the circuit in the charger. That did not work with E7.

If you short D+ and D- it should work, I've even done this with leaving the resistor network in place because for the charger I adapted the resistor values were high enough that the leak currents were minimal.

All of this assuming the E7 is as standard about charging as the n900 is....

Ok, i finally found out a way to get it working.
I unbridged D+/- and bridged V+ to D- and V- to D+.
So i was able to mod my iphone charger to work with the E7.