Concatemerization of miRNA... - (Oct/23/2009 )

I get 2 bands on agarose gel on running my qPCR products for some miRNAs whereas a few others show just one band around 25bp(expected size). I believe the ones for 2 bands are mature and precursor miRNAs. Has anyone seen concatemerization of some miRNAs whereas some others not showing this??

Thanks!!

I wonder which realtime PCR kit you used. Should you get 100-150 bp band?
I don't think 25bp should be the expected/correct size.