Auto Restart Issue with Mac Book AIR

Question

Have been using a Macbook PRO for sometime, no problem with Parallel installed. Due to frequent traveling, light and compact is my priority now, so I bought another AIR (11" i7 chip w/ Parallel installed as well). It was working flawlessly for few weeks, used it to download a couple of updates when I was in China (approx. 4Mbit/sec line speed) still no issues. UNTIL when I get back to my office and using WIFI updated another few stuffs, the AIR started to behave strangely with "your computer needs to restart due to problem ..."  the last few days it happened at least 10 times daily, so I did what I know with the usual Mac way,  reset PRAM, repair permissions blah blah blah ..problems persists so I called the service centre and the technician I talked to suggested the issue could be from 'your moderate internet speed causing incomplete system updated files.' ;  half convinced but I followed / reinstalled ...with no CD, it has to press option to select  to reinstall -- only then I realized a big problem, originally it states requires 27 hours to reinstall a fresh LION in my AIR but finally it completed and restated in still about MASSIVE 7-1/2 hours time. 
As I have bought a USB network connector now (a convenient gadget when stays at hotels with different levels of facilities offered), this is not so troublesome and I think fellow users should consider using network and avoid using WIFI for this purpose. I notice once the left USB once was used (without turning off the WIFI)  it keeps breaking the connections, as I read some articles from this forum the left USB could has some stability issues.  After all the time spent, the computer freezes at times and auto restarts again. What the heck has this causes the AIR to behave this way ?
NEXT, I also read on the Power issues, I bought it without realizing one of the technical highlight is on high performance battery management but you can chop my head off and sit on mine if the AIR can last 3 hours (probably the suggested time is with computer power on but without using it at all). I don't want to sound un-nice as I have been using Mac for many many years:  1) if AIR is entirely basing on internet (VERY HIGH SPEED) for support is not a really very friendly method for users if there is reliability issues via internet line support, says what if we are caught in remote area with 30k/sec line speed then we are totally dead ... ; 2)  the recent scare makes me dare not using the software updates now, as technician suggested, write down what is required to update, find it from apple and do it manually ...Goohs, my Mac Book Pro using side by side doesn't has this issue.   Since when was the last time I have to suffer maintaining a Mac myself ? ...  @%#&@*!(!
Anyone has clue to these or simply return to service centre to handle for me ?
Thanks in advance (first time user in this community).

Answer 1

Hello!
I´m sorry it took so long to reply, but I´m new to these blogs; and I´ve been travelling a lot... Anyway, I was able to configure Airport Express, but I was told I could use it to expand my wireless network inside my house; which I found it´s not possible.
So, I´m returning my Airport Express to the store tomorrow and try to figure out a way to extend my wireless in any other way.
Any sugestion? Big houses are a problem...
Best regards, and once again thank you!
Antonio