i have called distributor,they said it was normal,dont matter it,
meanwhile i have written to Klipsh support about the box ,
they said it can be opened box and asked where i have bought it,i answered their email,
then yesterday the distributor called me,they said it was a DEMO product and if i want i would send it back and they would send a new one in a 1 month,
of course i said i will send it back and not to wait if there is rb61, i would buy it paying over rb51 price
yesterday i send back rb51,and paid over for rb61,now i wait for rb61 next week.
rb51 was as new,they say they have only showed someone it and put in the box but they didnt say that to me when i bought it,i think that was a shame for them.
and thanx Klipsch support