Have you had any experience with OleDB.Oracle? I have installed 11gR2 client and linked server on 2008R2SP1 and queries under 100 rows works fine but anything over gives an error...

I get OLE DB provider "OraOLEDB.Oracle" for linked server "ORA" returned message "ORA-01403: no data found".

Msg 7346, Level 16, State 2, Line 1