Maybe power isn't enough, try other otg cable ?
Sony center is ur best choice

Yes. It can detect my Samsung 1TB usb harddrive ( fat32). Sometimes is cable problem. I have 3 n only one can detect it.

Later I will post photos of my 3 cable n all looks different. You just got to buy from another supplier n test it till you can find one that works. Cable is darn cheap around rm10+ only.
What is crazy screen sensitivity
Suggest to use SP as the anti shatter film is easily scratchable. And yes with SP applied sensitivity is reduced as I tested n cannot even write properly n recognition gets poorer too. Other usage of pencil or finger contact not much difference.

Looks like is your touch screen problem
Try factory reset to see whether it improves
If still same send in service center to check
Never faced such issues in my previous 3g model n current LTE model
I don't think is due to SP or if so maybe quality of SP. Or try remove SP. I am using Niilkin SP
Just explore yourself to find the solution

My previous one also crazy. Sometimes go haywire but my second unit is fine.

You can always use any glass cleaner liquid ( i used my specs lens cleaner ) to clean the display before and after removing SP> And I have yet to experienced /seen any SP that leaves any sticky residue behind
I would say is a BIG SIN to use matte SP for this phone as it will mask the beautiful display
This is the pic of my 3 USB OTG cable arranged in order of my preference of use. The smallest unit is the only one that can read my 1TB USB drive

[attachmentid=3680244]
For 3G model, only ver 510 available : http://forum.xda-developers.com/xperia-z-ultra/development and you need CWM installed to flash it
Busybox is just a simple installation - there shouldn't be any issues at all installing it. Try download from playstore gain to install it if you have issues

I sold it to another forumer. Some forumer say it's normal as it happen to theirs too 

Possible is the screen protector. Try remove it and clean the screen.

ya. it is free on ios.. i still waste 0.99 us to buy the game when the game release..   

Don't think the police will layan u on such small case.
Most probably they will say " who ask u to bring to school at first place? "
Or unless you have real solid evidence ...
or u have some " connections " to make them investigate for you.

I'm not shooting the police or making fun of u...
I lost something last time, got a suspect, reported police,
He said : WHY U LEAVE IT THERE AT FIRST PLACE ? What's ur purpose of reporting now ? We can't bring in anyone without evidence.

In the end,I be my own detective and caught the sucker who stole my stuff .

Look at the bright side, u don't have to worry how much u have to sell ur no logo z ultra...haha...jokin.
Good luck. Keep us updated.

hidden spy cam caught him using my phone.. caught him red handed, check imei with box ... boom... demand him to pay full price of my phone...he got the phone he wanted so much.. I got my money back for newer phone... case closed.
give him a chance, tell the suspects to courier back to u or secretly put somewhere for you to collect without knowing his identity. because even if he realized he is wrong now. he wouldn't dare to admit also.
and if u keep pressuring him,  most probably he would keep denying or hide the phone or even just throw away. so what if u have eye witness, you are not bringing this case to court also. even if u bring in the police, they can't do much with just a few witnesses.

Use gotya! Or Cerberus apps for anti theft( paid).. Install smart lock screen protector (free) to prevent ppl turn off your phone.. Of course need set pin or pattern or password for lock screen.

Can capture ppl face if wrong attempt, location, ring up, remote control, theft change sim will get notify to your preferred number and more.. I like this..

In my dream only

Btw my mom ady agree me to buy new phone BUT Don't bring phone to school anymore if not she will rampas

SPM? I already cuti liao lol no school anymore

No, police no action also... sien

Confirmed is my friend stole my phone

But I think the stupid already turn my phone to cash la long time ago liao

iPhone 3GS for temp But still can't decide what phone to buy soon...

4.5k bro. Not only phone lost, my XZU flip case inside have RM200 cash also.

XZU RM2100 + Iphone 5 RM2200 + RM200 cash = RM4500

I sold after I lost my phone

I think XZU no worth 1.4k, my XZU already crack like hell, if you refer to my previous post. 1k is max i think. iPhone 5 yeah 1.6k

5S out of my budget. My cousin suggest me wait for next year de phone. maybe upgrade to 64 bit ady