AT&T LG G2 - phone blending SMS frim stock text app

[Guyute278]

This is an issue I had thought was akin to my old iPhone that i wouldn't have to worry about anymore. Occasionally, when I send a text to someone, it will blend with another, often extremely old, message that was sent to someone else. The mixing typically occurs within a word, where the first part of a word from my new text entwines with the last part of a word from an older text, and then, the rest of the old message. Also, it usually occurs on a message I've gotten hung up in, gone back and edited to fix errors or just reword, before sending out. Every time I think, but I could be wrong. I have seen other people have this same problem in the past, but weren't given an explanation. Is this a virus? I have done a lot of "outside the box" downloading on both phones. Please advise; this is very frustrating, and I panic each time I send an SMS. I am aware of how great GoSMS is...I'm just looking for an explanation at this point. Thanks.