$3.30 on FT - Min donk bets confuse me

[Prodigy54321]

I have been playing very tight at this table for a while..mid tourney..a little less than the average stack

I have never been able to figure out what these minbets mean..I often get advice to raise them as if they were a check as I did...but people don't seem to ever fold to my raises in spots like this on the flop..maybe it's just because it's such a low buyin...

anyway..advice on the whole line is appreciated...

should I just fold on the river to the minbet?

Full Tilt Poker
No Limit Holdem Tournament
Blinds: t150/t300
(Ante: t25)
9 players
Converter

Stack sizes:
UTG: t3660
UTG+1: t1920
MP1: t4615
MP2: t840
MP3: t3135
Hero: t7355
Button: t2785
SB: t2550
BB: t5805

Pre-flop: (9 players) Hero is CO with K[img]/images/graemlins/diamond.gif[/img] Q[img]/images/graemlins/heart.gif[/img]
5 folds, <font color="#cc0000">Hero raises to t800</font>, 2 folds, BB calls t500 <font color="aaaaaa">(pot was t1475)</font>.

Flop: 5[img]/images/graemlins/club.gif[/img] A[img]/images/graemlins/spade.gif[/img] 8[img]/images/graemlins/heart.gif[/img] (t1975, 2 players)
<font color="#cc0000">BB bets t300</font>, <font color="#cc0000">Hero raises to t1500</font>, BB calls t1200 <font color="aaaaaa">(pot was t3775)</font>.

Turn: J[img]/images/graemlins/diamond.gif[/img] (t4975, 2 players)
BB checks, Hero checks.

River: 6[img]/images/graemlins/spade.gif[/img] (t4975, 2 players)
<font color="#cc0000">BB bets t300</font>, Hero ???