I checked out the article by tuaw: http://www.tuaw.com/2010/08/13/hardware-test-your-iphone-4/ And idk if its me or not..but my iphone 4 replacement (4.0.1 jb, no shsh blobs, sorry) seems a bit jerky or laggy most of the time (even when im not running too many apps, or closed some out the multitasking window). Everything else runs fine (no proxy troubles, dead pixels, nada), it does heat up at times, but cools down. Like for example, if i open the camera app, it might take a minute to open, or if i close it, sometimes it wont close like a regular app, it just goes to the home screen. I was wondering if there there's a program i can use to tell or method i could do. So far i took a snap shoot of istAT: (in the attachment) Maybe this is just a software issue. Idk thats way I came to you guys first. I shouldnt have to get another replacement or anything right? PS I think i spelled thoroughly wrong so excuse me lol. And I added the TUAW link.