There's nothing wrong. Sometimes you should 3-bet or call and raise the turn. However, you must remember that villain can have just a weak hand, but it's still ahead of yours. I'm convinced that in all of these hands, the villains had two overcards and were playing the same chasing game that you want to play. (Edit: What I had here a moment ago wasn't correct. The second two cases were chasing 6 outs and getting 6:1. It barely works out to barely profitable if you include one more bet on the river. However, they could just as easily be drawing to 3 outs, making it highly UNprofitable.)
Party Poker 0.50/1 Hold'em (9 handed)
internettexasholdem.com
Preflop: Hero is BB with 7[img]/images/graemlins/heart.gif[/img], K[img]/images/graemlins/heart.gif[/img].
<font color="#666666">
2 folds</font>, <font color="#CC3333">MP1 raises</font>, <font color="#666666">
5 folds</font>, Hero calls.
Flop: (4.50 SB) 5[img]/images/graemlins/club.gif[/img], T[img]/images/graemlins/heart.gif[/img], 7[img]/images/graemlins/diamond.gif[/img] <font color="#0000FF">(2 players)</font>
Hero checks, <font color="#CC3333">MP1 bets</font>, <font color="#CC3333">Hero raises</font>, MP1 calls.
Turn: (4.25 BB) J[img]/images/graemlins/spade.gif[/img] <font color="#0000FF">(2 players)</font>
<font color="#CC3333">Hero bets</font>, MP1 folds.
Final Pot: 5.25 BB
===
Party Poker 0.50/1 Hold'em (9 handed)
internettexasholdem.com
Preflop: Hero is BB with 4[img]/images/graemlins/heart.gif[/img], 4[img]/images/graemlins/club.gif[/img].
<font color="#666666">
5 folds</font>, CO calls, <font color="#CC3333">Button raises</font>, <font color="#666666">
1 fold</font>, Hero calls, CO calls.
Flop: (6.50 SB) 6[img]/images/graemlins/spade.gif[/img], 3[img]/images/graemlins/diamond.gif[/img], 8[img]/images/graemlins/diamond.gif[/img] <font color="#0000FF">(3 players)</font>
Hero checks, CO checks, <font color="#CC3333">Button bets</font>, <font color="#CC3333">Hero raises</font>, CO folds, Button calls.
Turn: (5.25 BB) 8[img]/images/graemlins/club.gif[/img] <font color="#0000FF">(2 players)</font>
<font color="#CC3333">Hero bets</font>, Button calls.
River: (7.25 BB) T[img]/images/graemlins/club.gif[/img] <font color="#0000FF">(2 players)</font>
<font color="#CC3333">Hero bets</font>, Button folds.
Final Pot: 8.25 BB
===
Party Poker 0.50/1 Hold'em (10 handed)
internettexasholdem.com
Preflop: Hero is UTG+1 with 5[img]/images/graemlins/heart.gif[/img], 5[img]/images/graemlins/club.gif[/img].
<font color="#666666">
1 fold</font>, Hero calls, <font color="#666666">
1 fold</font>, <font color="#CC3333">MP1 raises</font>, <font color="#666666">
6 folds</font>, Hero calls.
Flop: (5.50 SB) 2[img]/images/graemlins/spade.gif[/img], 6[img]/images/graemlins/diamond.gif[/img], 6[img]/images/graemlins/spade.gif[/img] <font color="#0000FF">(2 players)</font>
Hero checks, <font color="#CC3333">MP1 bets</font>, <font color="#CC3333">Hero raises</font>, MP1 calls.
Turn: (4.75 BB) J[img]/images/graemlins/diamond.gif[/img] <font color="#0000FF">(2 players)</font>
<font color="#CC3333">Hero bets</font>, MP1 calls.
River: (6.75 BB) 3[img]/images/graemlins/spade.gif[/img] <font color="#0000FF">(2 players)</font>
<font color="#CC3333">Hero bets</font>, MP1 folds.
Final Pot: 7.75 BB
===
And here's an example of why you should be careful when you *DO* have overcards (especially an ace or king):
Party Poker 0.50/1 Hold'em (10 handed)
internettexasholdem.com
Preflop: Hero is BB with K[img]/images/graemlins/diamond.gif[/img], 6[img]/images/graemlins/diamond.gif[/img].
<font color="#666666">
5 folds</font>, <font color="#CC3333">MP3 raises</font>, <font color="#666666">
3 folds</font>, Hero calls.
Flop: (4.50 SB) 6[img]/images/graemlins/spade.gif[/img], T[img]/images/graemlins/club.gif[/img], 4[img]/images/graemlins/heart.gif[/img] <font color="#0000FF">(2 players)</font>
Hero checks, <font color="#CC3333">MP3 bets</font>, <font color="#CC3333">Hero raises</font>, MP3 calls.
Turn: (4.25 BB) K[img]/images/graemlins/spade.gif[/img] <font color="#0000FF">(2 players)</font>
<font color="#CC3333">Hero bets</font>, <font color="#CC3333">MP3 raises</font>, <font color="#CC3333">Hero 3-bets</font>, MP3 calls.
River: (10.25 BB) 4[img]/images/graemlins/club.gif[/img] <font color="#0000FF">(2 players)</font>
<font color="#CC3333">Hero bets</font>, <font color="#CC3333">MP3 raises</font>, <font color="#CC3333">Hero 3-bets</font>, MP3 calls.
Final Pot: 16.25 BB
Results in white below: <font color="#FFFFFF">
Hero has Kd 6d (two pair, kings and sixes).
MP3 has Ah Kc (two pair, kings and fours).
Outcome: Hero wins 16.25 BB. </font>