Whenever I receive a text message the number starts with a +61 and I do not know who the message is from even when it's from one of my contacts that is saved without the int. roam code. Can you please tell me how to stop that from happening?

Go to contact list and see if the number is listed. IF it is, press the number and hold, you should get a pop up with a menu that has block checked on it. Uncheck it.

If you're putting a "1" in front of the number (eg. 1-123-555-1234) try taking it off, or adding it onto the number your are trying to text, and try calling it to make sure you typed the number correctly. You, or someone could've accidently went into your contacts and inadvertantly modified the number you are trying to text.

try just using her number instead of the contact u made ie just either remove the contact and then send her a text with the number she has correctly

This often will happen for interstates or overseas contact, when you enter your contact number without Country and/or Area code and the received number is 'different' like completely specified (or the other way around):
1). On your contact, Smith number is 0123 456789 but you receive +61 3 123 456789 (this is the most likely scenario for you as you can reply properly)
2) your contact, Smith number is +61 3 123 456789 but you receive 0123 456789 (as an example, they are calling using VOIP and can specify the number they transmit)
Solution is to look at you phone log and enter the number EXACTLY as received even as an additional number.
Hope it helps let me know how you go!

you need to change all your contacts to +44 numbers!! Very time consuming I know but it does work

This is an international symbol on the start of area codes. IE I live in Australia ans text messages received from other Australian mobiles have +61 which is the AUS international area code. If you replace the +61 with a 0 (in the case of AUS text messages) this is now the full mobile number the text was received from. Hope this helps.

you need to enter the message center number as per the subscriber so just contact your mobile operateor

On every phone there are settings that can stop you sending texts. However all phones should still receive texts even if all the settings were changed. As the text message is directed to you mobile number you should still be receiving?
When you compose your text and select contact does the phone move them to the out/sent box?
Settings to check for sending are your 'message centre number' (your network provider can supply and they are normally different for pay monthly and pay & go) 'Message sent as' should be 'text' (not fax or email etc).
Text problems are common where people change or delete digits from the message centre number by mistake.
If you cannot receive texts i would recommend speaking to your provider for help as it may be your account details at their end? (beyond your control). Hope that helps?

I have the phone and have had the same problem. I found I have to add the "1" before the area code to all the saved contacts or at least the ones you use most and that should fix it... when the text message is received it has the "1" normally we don't save the number that way...

this might be a network thing because that is the only way it works here in Australia.
All txt msgs are number only ID