invalid floating ...?

hi,

i had an application written delphi6 with BDE 5.1. i had used standart BDE
components, and it was working. Then i installed D6 to another computer,
defined BDE aliases. But when i try to run the same application in this new
computer, i get an error message :

"Project xxx raised exception class EInvalidOp with message 'Invalid
Floating Point Operation'."

an sql statement in a TQuery component raised this error message. because
when i run the program by closing this component, it works. in sql statement
there are two tables joining with their numeric fields.

how can i solve this problem?

thanks.