Error in Power path devices.

Red Hat Enterprise Linux Server release 5.1 (Tikanga)
2.6.18-53.1.14.el5 #1 SMP Tue Feb 19 07:18:46 EST 2008 x86_64 x86_64 x86_64 GNU/Linux

# powermt display
Symmetrix logical device count=12
CLARiiON logical device count=6
Hitachi logical device count=0
Invista logical device count=0
HP xp logical device count=0
Ess logical device count=0
HP HSx logical device count=0
===================================================
===========================
----- Host Bus Adapters --------- ------ I/O Paths ----- ------ Stats ------
### HW Path Summary Total Dead IO/Sec Q-IOs Errors
===================================================
===========================
3 qla2xxx optimal 24 0 - 0 443
4 qla2xxx optimal 24 0 - 0 0


Also i see the below statistics from the same HBA

"Commands retried with dropped frame(s) = 513"
======
QLogic PCI to Fibre Channel Host Adapter for QLA2460:
Firmware version 4.00.26 [IP] , Driver version 8.01.07.15
ISP: ISP2422
Request Queue = 0x449c00000, Response Queue = 0x44c4d0000
Request Queue count = 4096, Response Queue count = 512
Total number of active commands = 0
Total number of interrupts = 94270
Device queue depth = 0x20
Number of free request entries = 222
Number of mailbox timeouts = 0
Number of ISP aborts = 0
Number of loop resyncs = 0
Number of retries for empty slots = 0
Number of reqs in pending_q= 0, retry_q= 0, done_q= 0, scsi_retry_q= 0
Host adapter:loop state = , flags = 0x1a43
Dpc flags = 0x4000000
MBX flags = 0x0
Link down Timeout = 030
Port down retry = 030
Login retry count = 030
Commands retried with dropped frame(s) = 513
Product ID = 0000 0000 0000 0000
===

Also there are messages about LUN tress passing between primary and alternate paths

whats your openion ? Will it due to defective cable or HBA or ? ?