Hi Manoj,
It is possible when the 'full stock removal requirement' indicator is not set for the storage type, for more details please refer below link.
http://help.sap.com/saphelp_erp60_sp/helpdata/en/c6/f847054afa11d182b90000e829fbfe/content.htm
I think the quant related to the first item in TO should have blocked, that's the reason it is not confirmed. But still it will show in the source storage bin under pick quantity and not under available stock. At the same time it will also show the quantity in destination bin under stock for putaway.
Please check whether there is any issue with the quant or material with batch number for the first item.
Regards
Vijay