Live with walkman touch button problems

[#1]

I bought the phone yesterday. Everything was alright, but today, at the evening, I noticed that touch buttons are malfunctioning. There are 2 touch buttons : Back and "Context" one if I'm right?

Basically when you double-tap "Context" button on the right, it brings "Search" or in other words "Type menu". If you just click on it it brings context menu. The problem is that it doesn't matter how many times I click the context menu button it always brings me the type menu, sometimes if I'm lucky I get the context menu there. 10 of 1 will bring the context menu. It brings context menu more often In walkman app. The back button sometimes doesnt' even work or respond slowly when I'm in settings. I didn't try update service, should I try it? Or should I just take my phone to warranty?

[#2]

I didn't take the phone to repair, but I know undestand how to avoid this problem.

If you don't click many times on the buttons , it will work good, also get your hands dry, not wet, if I click the buttons in 10 seconds interval it is ok. But when I click the button more than 3 times it stops responding. I think new updates for the phone will fix this.