are you playing blitz, or long games?
cannot see en prise pieces

I try to play long games, as long as possible. I avoid internet play since here everyone plays like 1 minutes lightning to 5 minutes blitz.

Yeah, keep doing chesstempo and the tactical trainer on chess.com. You will start recognizing the patterns.
A good book like chess tactics for students by john bain, can help you see the forest through the trees because it gives the full classification of the tactics on paper, with paper based exercises. Some people learn better by writing stuff than by just clicking and you can make your pattern recognition more solid faster.

I try to play long games, as long as possible. I avoid internet play since here everyone plays like 1 minutes lightning to 5 minutes blitz.
Ummm surely NOT everyone!
For example, most of the games i play are between 15 and 30 minute ones. I think the WWW is a wonderful place to play chess. Some other nice sites are ICC and FICS.
Keep playing and studying and working on chess in order to get better... Chess is a great and very "deep" game!
Oh, and don't worry about your age... you cannot change that, anyway :D

ok ok but my primary problem is that there is a barrier sometimes that prevents me to SEE pieces on the board, it's like selective vision or something like that! it's very annoying. thanks for the suggestions anyway.

ok ok but my primary problem is that there is a barrier sometimes that prevents me to SEE pieces on the board, it's like selective vision or something like that! it's very annoying.
I think it's a matter of training... It still happens to me sometimes, after years of (casually) playing chess. Indeed it's annoying, but also funny :D It's there in front of your eyes, in those 64 squares, one of those 32 -or less- pieces, but you just miss it, or forget about it completely! It's like running in a marathon, but stumbling and falling down breaking your leg - but it hurts much less, thankfully :D
Makes you wonder what other things you are missing in your everyday life...
Oh, here's a relative article http://www.chess.com/article/view/counting-vs-counting-material

ok ok but my primary problem is that there is a barrier sometimes that prevents me to SEE pieces on the board, it's like selective vision or something like that! it's very annoying. thanks for the suggestions anyway.
It's hard to point out a specific problem you're having over the internet... mostly because what you describe is true for every beginner :) The more you play the more you'll start to recognize recurring patterns of attack and defense. Key among these patterns are always undefended pieces or an exposed king (more on that below).
I'll just say, remember that your opponent always has options. Lets say you move a pawn to attack one of his pawns. Do you assume he will capture? For example he may be able to:
1). Defend (or re-defend) his attacked pawn.
2). Capture your pawn.
3). Push his pawn forward so it's not attacked anymore.
4). Make a threat of his own not involving the pawn.
5). Ignore the attack and make a move somewhere else in general.
I think it's common when a piece is dropped the mistake is we assume our opponent will play a certain move, and we forget he has many options... not only that but he will always pick the option that he thinks is most unpleasant for us!
So your job is to find the most unpleasant move your opponent can respond with. So make it a habit of noticing all the captures and checks your opponent can play in response to an intended move. Especially ones involving your undefended pieces... these are certainly the "unpleasant" moves your opponent will look for immediately after you move.
This is Heisman's advice, not my own (a player, author, and coach). The advice sounds very simple but it takes a lot of practice to do it consistently.
Hello everyone.
This is my first post.
I am a novice chess player, have been studying "seriously" for about 2 months. I'm also 36 years old, so my age is quite a disadvantage for learning, from what I read around.
Anyway, one of my most annoying problems is that I can't see "en prise" pieces. I bought Fritz 11 cheap edition a month ago on amazon (extraplay reissue) and it has a nice training feature "Attack training", and I often manage to "forget" 2 or 3 pieces under attack, without clicking them.
Another problem is that I can't seem to know how to play safely in real games... I give away pieces over pieces like a bleeding artery.
I definitely feel very stupid. On chesstempo I have a rating of around 800...