I'm having this issue on a procurve switch. I get a ping time out after about every 100 succesful pings. I took a look at the log and saw this.
Saved Crash Information (most recent first):
SubSystem 0 went down: 01/01/90 01:41:24
Bus error: HW Addr=0x40000180 IP=0x002960f0 PCW:0x00000003 ACW:0x00001004 Task=
pfp: 0x00af1c00 sp:0x00af1c80 rip:0x002960f0
Saved Crash Information (most recent first):
SubSystem 0 went down: 01/01/90 01:41:24
Bus error: HW Addr=0x40000180 IP=0x002960f0 PCW:0x00000003 ACW:0x00001004 Task=
pfp: 0x00af1c00 sp:0x00af1c80 rip:0x002960f0