caching too much

[A]

Hello
I have a caching problem : my WebService is using a DB.
I'm doing changes in the DB and they are not reflected in the result of the Web method.
After like 30min, restarting IIS many times .... without touching the code, the changes appear in the result of the Web method.

I try to add [WebMethod(BufferResponse=isBuffering)] but it keeps the same data...

Thank you,
Alina