Thank you for the info, juiceme In the meanwhile, I tried connecting the charger to an iPhone and the touch was working properly.

@pichlo & others: Yeah, as suggested, I tried using the compass while charging and I couldn't find any deflections which further verifies that it isn't something caused because of EM waves. The better option would be buying a better charger

Update: Bought a new USB charger (Original, LG) and I am no more facing any issues with the touch screen.

Meanwhile, I've found out a workaround with the faulty charger Connect a USB extension cable to the charger first and then connect the Nokia USB cable to this extension cable, and then charge. This solved the issue for me and the touch screen responds normally while charging. I am using a 0.5m USB extension cable.

I get the same when use blackberry charger, but there is a way to handle it:
screen is laggy when you wake up the phone by button, so when i do double tap on screen to wake up, problem with bad response disappears.

On similar lines, I had an issue with a samsung charger that works perfectly fine otherwise. I'd visuted one of my cousins recently. On plygging in the charger to one of their power ports made my fon go crazily switch between charging and not charging to charging etc.

it worked in the rest of the house though. Just curious to know what may be the reason

I would certainly look at that socket. Dodgy wiring may cause fire.

ya, this is cause by third party charger cable quality(magnetic problem that will disturb the g-sensor inside n9, which will hard to swipe up/down/left/right) while pluging the cable.

where did you get the charger? I am having same problems with my nokia charger.
thanks.

I got the mass storage/sync notification one time i connect the original charger with a Lumia cable

The new LG one? Bought it from a local store. You have problems with your Nokia N9's original charger? That's sad. Better get a new charger before you damage your phone

Hi fellow n9 users,

I've used my N9 for 'bout 4 weeks now and faced the same issue being dicussed in this thread.

Anyway.. I ordered a new (?!) N9 from an online shop in Germany, so I got a nice blue box with sticker saying "South Africa" on it.

It all began with a non-responding screen after unlocking and immediately being asked to quit flight mode (which was active that time) - no matter how I touched, swiped or whatever - the phone did not respond... until I pulled the charger plug!

Charging via the Nokia USB Cable is just fine, but recently I plugged in the original charger that came with the n9 (like fire & forget) late at night to have a fully charged phone next morning - to discover it had not been charged. Next morning it was at 75% so I wondered what the heck was going on...

Further investigation gave following results:
1 - The charger that came with the phone is not recognized as a dull charger, but as a USB data cable, 'cause the phone asks me which USB mode to select.
2 - it obviously has a very bad contact, when changing the position of the phone with charger attached to it, it changes from "phone is charging" to "not enough power to charge"...
3 - Just coz I was pissed bout above mentioned, I attached my sons Samsung micro-USB charger with 700 mA and wow - charging the battery like hell, without any further mention of "which USB data mode would ya like to select for your connected charger"...

The charger that came with the phone is Nokia AC-6E which says it will output 5V with 550 mA. I have my doubts that this should be the n9 stock charger. Can anyone confirm the model number or my weird experiences??