Did you apply the recommended patches? They would be outlined in the in 8.1.7 Oracle Release notes. According to
http://bizforums.itrc.hp.com/cm/QuestionAnswer/1,,0xbdc153921f1ad5118fef0090279cd0f9,00.html it's also on the oracle metalink under "131235.1"
From this post:
For information on required HP-UX patches, see
[NOTE:43507.1] It is strongly recommended that these HP patches are applied. Please note the following patches, which are mentioned in the CD Release Notes (Part number: A86566-01),
are included in Note:43507.1
PHSS_21947 (ld(1) and linker tools cumulative patch)
PHNE_20316 (Cumulative STREAMS Patch)
PHKL_21392 (VxFS performance, hang, icache DPFs)
PHKL_22145 (signal, threads, spinlock, scheduler, IDS)
PHKL_22266 (LVM Cumulative Patch)
Cheryl
"Downtime is a Crime."