Oracle has reported a new Alert for user’s who have upgraded their databases to 10.2.0.3 patchset on windows.
User processes dumps core dumps with following errors
ORA-07445: exception encountered: core dump [<strong>opidsa()</strong>+480] [SIGSEGV] [Address not mapped to object] [0x000000000]  
ORA-07445: exception encountered: core dump [ACCESS_VIOLATION] [_opidsa+360] [PC:0x2080540] [ADDR:0x0] [UNABLE_TO_READ] 
Patch 5648872 can be applied to resolve the issue. For more information, refer to
Metalink Note:418531.1-ORA-7445[opidsa] after Applying the 10.2.0.3 Patch Set
This issue is fixed in 10.2.0.4 Patchset