Strange wifi problem on a brand-new MacBook Pro

Question

Hey there, I'm new here. Desperation has got the better of me, and I hope I can get some advice.
So, last sunday I bought a brand new 13" MacBookPro with 2.8g i7 processor and 10.7.2 OS (I can't update to 10.7.4 because System Update tells me the download has been tampered with or corrupted after I waited 2 hours for it to finish, but I'm trying a direct download from the website). Here's the exact product: http://www.amazon.com/Apple-MacBook-MD314LL-13-3-Inch-VERSION/dp/B005CWIZ4O/ref= sr_1_5?ie=UTF8&qid=1340301247&sr=8-5&keywords=macbook+pro+13
Everything is all perfect except for a strange wifi problem. Note that the wifi does not turn-on or off, it doesn't disconnect after 'sleep', it doesn't get less speed, it doesn't constantly leave a preferred connection (once I chose my home wifi it always connects to it no problem). The wifi bar is always full. What is wrong is that the internet is kinda 'glitchy'. The best metaphor I can think of is that it's like a car that has to be pushed down the road before the engine can start. Please, bear with me because this is kinda hard to explain and I'm not good at tech lingos.
One of the symptoms is browsing can get really slow and inconsistent, almost as if the wifi gets turned off in the middle of browsing. For example: if I look something up on Google and then open 5 new tabs, probably only 2 or 3 of those tabs will eventually load while the other two will not get past the long 'http:.......google.....etc etc' address and will eventually show one of those 'error loading page because there's no Internet connection' notice. This happens a lot. Sometimes I have to refresh/retry loading a page a couple of times before it finally loads, then usually everything will get back to normal and I will be able to open multiple tabs with no problem, but in a couple of minutes I would try to open another site and the problem will start again.
So I tried to see how it does with downloading using iGetter. Fortunately I also have a Macbook (white-plastic casing one) and my brother has an old 2006 MacbookPro so I can compare. With those two older Apples iGetter starts receiving data in less than 8 seconds after I click Start, while my brand-new Macbook Pro can take up to 15-20 seconds, sometimes it doesn't even start at all and I have to re-click the start button. But once the download actually starts (on my new MacBook Pro), it downloads like normal, it doesn't stop and the speed is also as good as I can get. Strange huh? Hence, like a car that has to be pushed before the engine starts.
I also tried 'speed testing' from a website with all 3 laptops. On my old MacBook and my brother's MacBook pro, once I click 'begin test' it takes only a couple of seconds of 'ping' before the download/upload speed measurements start, but with my new MacBook Pro (just like with iGetter) it takes up to almost a minute before the measurements start, sometimes it won't start at all and I have to re-start the test.
Well, thanks for reading. And hope you can help me shed some light into this. Because it is really preventing me from really enjoying my new MacBook Pro. And if this is most likely a hardware problem, I'd better get back to the store and try to get it replace or something while it's only been 5 days. *cheers*

Answer 1

Hey guys.. Thanks for the replies. Unfortunately, I bought the MacBook in Indonesia where there are no such thing as an AppleCare. The only option is to leave the Apple product to one of the 'Authorized Apple care centre' and have whoever do whatever to it without guarantee of success. As for returning it and getting a brand new one, I also don't know if there is such a deal here, but that's actually a good idea, will try to go to the store tomorrow. Although, I'm worried that the problem might be with OSX Lion or something and getting a new one won't help.
mark75090, I've tried resetting the router when I first noticed te problem, didn't work though. I've checked my new MacBook's wi-fi (option+click wifi bar) and it says 'PHY Mode: 802.11g', so does my MacBook and the old MacBook Pro. I don't know what those mean though, and I don't know whether or not my router is an N., can you tell me more please.. I have tried with the other two turned off, and only the new MacBook using the wi-fi but the problem persists. I have also tried connecting directly to the router, but as I described, the problem is too subtle for me to notice the difference.
Also, if I create a brand new Wi-Fi connection in network preferences and connect to my router through the new Wi-Fi profile, the problem seems to be gone for an hour or so, then it always comes back though. I have also just finally installed 10.7.4, but it doesn't help either.