I'd suggest you update to an even newer current as some PCI retry 
configuration tweak (exspecially for U10 machines, IIRC) went in later.

Additional (but this may be only me) tweaking the value of "block_disable"
(in sys/arch/sparc64/sparc64/locore.s) to 1 is a good idea. The effects
this showed for me when set to 0 (the default in -current) are not yet fully
analyzed, so this change might as well not be necessary.

Martin