I/R Scope Problems. Am I the only one?

Before I start, I should say that I am a long time COD player, new to battlefield. And I am just loving BF3, for the look, the feel, the realism and the rush of the game. Now on to the point.
I hated the thermal scopes in COD, and I positively LOVE them here in BF3. They light enemies up like. . .like. . .like a very bright thing indeed. But I keep coming up with the same problem over and over again.
Sometimes, enemies simply won't appear in my thermal vision.
No, it's not a range issue. No, it's not a black SpecOps camo issue. I can be five feet from someone, staring right at them, and they simply won't appear. Not at all. Even as a dingy outline. Go back to hip-fire, there. Back to thermal, gone.
I walked into a room on Sienne Crossing, during a rush game, trying to disarm the B objective on the third push-back. Came up to the room, swept it with my thermal scope to be certain nobody was hiding, ran in, and promptly got shot in the back for my troubles. I didn't miss the corners. They weren't behind a crate. They just didn't appear, and I stopped paying attention once I thought they weren't there, running straight for B.
The worst part is there were TWO of them, and NEITHER showed up. I just can't fugure this out. Is it a glitch? A hack? What?

I am going to guess just another issue that needs to be fixed. I personally haven't used them much .... YET. I may decide to use them more later on. Right now I just roll with the simple things, LOL.

I'll go with DT on that...prolly a glitch. Ive noticed that if they are backlit they dont show up as well, but never had a problem indoors. Unfortunately, I hear they r gonna nerf the IRNV scope. Too bad, cuz I wear people out with bitch right now. Its a game changer in Squad Rush for sure.

well i dont think its a glitch. This weekend i came a cross a player "HIGHROLLER451" on xbox live who was not showing up on my IR Scope. I TOO thought it was a glitch but i saw him moving so i was able to sneak in behind him and i went for a knife kill but got nothing. i swung 3 times and he did not die!!! so i saw him moving because he most likely heard me slashing away so I EMPTIED A CLIP IN HIS BACK FROM 2 FEET AWAY!!!!!!! NOTHING!!!!!!! he did not die. he killed me then a squad medic revived me and when i came to there was a semi circle of my team around him shooting away with NO results.... this bastard was running around trying to knife people the whole match. My squad all reported him. i hope everyone on our team did. I was freaken furious. flat out cheating to rank up or get unlocks. PATHETIC!!!!! The next round he was showing up so maybe he turned off his cheater BS. that guy is garbage. i hope he gets banned.

Well im unable to edit my last post for some reason but the CORRECT gamertag of the cheater is HIGHROLLER451