I have the original battery that came with the Thunderbolt. I noticed if I'm using mobile web for maybe over 20 minutes or so, I can feel the battery heating up. Is anyone else experiencing this with the original battery? Is this "normal"? I don't notice it heating up when I just text or use the phone for voice calls. It's past the 14d period when I can return the phone. My laptop was doing the same thing (heating up), until finally it "burned out" the inside and has had to be repaired several times. I'd HATE for the same thing tohappen to my Thunderbolt, especially since I have 2 years with it. (Footnote: I did not purchase the extended warranty.) Help!!!