It won't change Anything, cause everything is in your iCloud from apple . iMessage is inside the iOS it self. Also try getting new wifi router, try the linksys E3000 wireless +N. it's either your iOS or wifi router. Or both of them.
"iMessage is an instant messenger service developed by Apple Inc. for iOS 5 and Mac OS X Mountain Lion.
iMessage was announced by Scott Forstall at his keynote speech on June 6, 2011 at the WWDC 2011. A version of the iOS Messages application with support for iMessage was included in the iOS 5 update on October 12, 2011.
As of December 2011 there are reports of stolen devices still sending and receiving messages of the original owner. In another case, an iPhone bought by a customer received iMessages sent to and by the employee who activated the iPhone.
On February 16, 2012, Apple announced that a new OS X Messages application with support for iMessages, replacing iChat, will be part of OS X Mountain Lion.
iMessage allows users to send texts, photos, videos, contact information, and group messages over Wi-Fi or 3G to other iOS 5 users, thus providing an alternative to standard SMS messaging for all users with devices running iOS 5.
iMessage is accessible through the Messages app on either an iPhone, iPad, or an iPod touch. Owners of these devices can register one or more email addresses with Apple, and, additionally, iPhone owners will have registered their phone numbers with Apple.
In Messages, a user can see if the other iMessage user is typing a message. Three pale blue dots/circles appear in the text bubble of the other user when a reply is started. It is also possible to start a conversation on one iOS device and continue it on another. iMessage-specific functions operate only between iOS 5 devices, such as an iPhone or iPad, but, on the iPhone, Messages can use SMS to communicate with non-iOS devices, or with other iPhones when iMessage is unavailable. On iPhones, green buttons and text bubbles indicate SMS-based communication; on all iOS devices, blue buttons and text bubbles indicate iMessage communication.
All iMessages are encrypted and can be tracked using delivery receipts. If the recipient enables Read Receipts, the sender will be notified when the recipient reads the message.
iMessage also allows users to set up chats with more than two people - a "group chat".
Message is based on XMPP, the eXtensible Messaging and Presence Protocol specification related to PubSub or Publish and Subscribe, the same system that's used for push notifications. By building a unified XMPP notification system into iOS, Apple provides push notifications, push messaging, and FaceTime call notifications without having to keep multiple open connections to several different IM chat provider services, while also avoiding additional dependence upon a mobile account required by SMS."
From, wikipedia.org ☣ ☢