ExecOpenScanR: failed to open relation

Hi,
in my java code I am creating 3 temporary tables, then calling a stored
procedure which calls another stored procedure.
then I drop the temporary tables. 

the first time around , eveything is OK  , then when repeating the action I
get 
"ExecOpenScanR: failed to open relation 2808495 "
could it be that an index exists when the table doesn't or
does it mean the functions did not stop properly ?
please help.
Pam Withnall