Hi Carel , we have got the same issue.
the ENV is the same as u said.
raised a tar already , sent the RDA output etc.
waiting for reply now.
i will let u know if there is any info from OSS.
meanwhile , let me know if you get any useful updates from OSS.
At a site I am today for the first time we get this error.
*** 2005-06-30 10:14:45.908
*** SESSION ID:(134.65095) 2005-06-30 10:14:45.907 Exception signal:
11 (SIGSEGV), code: 1 (Address not mapped to object),
addr: 0xfdaf0000, PC: [0x2469e8, ksmarfg()+640]
*** 2005-06-30 10:14:45.989
ksedmp: internal or fatal errorORA-07445
: exception encountered: core dump [ksmarfg()+640] [SIGSEGV]
[Address not mapped to object] [0xFDAF0000]  
It started a couple of days ago, and seems to occur more and more frequently.
Version is 126.96.36.199.0, OS is SunOS 5.8
Google and metalink seem to be of no help.