run time error "driver not loaded" for sqlite.

i m getting the error "driver not loaded" when running the application from a folder (say release/bin) but while running the same exe from a sub directory called sqldrivers(where i have put the drivers copied from qt/plugins/sqldrivers) under it , its running fine.

i have copied the the contents of sqldrivers to release/bin and tried to run that exe. again the same error.

i have other exes that uses sqlite and running fine from the same location.due to many reasons i want my exe at realease/bin.

what might be the problem?

being precise the error message is like this:
dbLocation = "c:\path\to\database.db"
QSQLdatabase: QSLITE driver not loaded.
QSQLdatabase: available drivers:
QSQLdatabase: an instance of QCoreApplication is needed for loading the driver plugins



Notes: I m using qt 4.6.1 on Windows XP with VS compiler.
the exes are qt testcases, that i want to run.

thanks in advance.