Iphone ''no service'' help?

Hi guys,

Newbie from the UK here, have an iphone 4 on Vodafone, and am having problems with the ''no service'' message.

You have probably had topics on this before?

And before you say search for the answer i already have

My phone is jailbroken and unlocked, and has been since August with no problems until now

Was using my phone at work last night, was browsing 'cydia' installed a few modz etc, then i left it for 30 mins, went back on to have another look and now cant get any signal!!

I have tried:

-switching the air plane mode on and off
-holding power and home button till it reboots
-tried turning off, left it for an hour and turned in back on
-reset network settings

And i stil have ''no service''!!!!!!!!

Any help would be appreciated

"installed a few modz etc"

That would seem to be where the problem started, so that's where I'd look first.