iPhone 4 : Invalid Sim Falilure for the Jail Broken ones!

After getting my hands on iPhone 4, all i have been doing for two days is researching on Jailbreak and Unlock. All the JB apps, Limera1n, ultrasnow, tinyumbrela.
Like others JB iPhone owners i am having two problems:
1. Battery Drainage : The battery gets fucked up real fast even without using the phone, but connected to WiFi.
2. Invalid Sim error: Whenever i try to restart the iPhone, i get invalid SIM failure.

I still haven't found out any good tips to cure the battery drainage problem. Well some say it's a jailbreak issue and will be fixed sooner, so hold on and be patience.
Out of blue, i think i have found the cure for the invalid SIM error, with brute Hit and Trial one. It has worked for me, hope it will for you lads too.

• Before switching off the iPhone make sure you disable the following things:-

1. Turn off the WiFi in Settings.

2. Turn off the mobile data (Setting->General->Network)

3. Disable the 3G ( Setting->General->Network)

• Switch off the Phone, and then Power on back.
• Hopefully, you might not get the SIM Invalid Failure message ;-)

 Try it out, and do write the comment if it worked for you or not.

Happy Jailbreaking!