No luck on my end either. On my 5th NetApp tech and they referred me to VMware support to resolve the issue. I'm waiting to hear back from them, but they've been awfully quiet.
I'm about to change the PSP to using FIXED with a preferred path as I've been working on this for months and I need to move on with this project. Maybe someone with more time can follow up on this and get this resolved once and for all since it doesn't sound like just me with this problem. I'm gonna dump my setup below and some of the steps I've taken:
SETUP:
Brocade VA-40FC 8Gbp FC switches (independent dual-fabric)
DELL R910/R900 servers with two single port Qlogic QLE2460 HBAs (each HBA to one fabric)
NetApp V3240 controllers with DataONTAP 8.0.2P4, single_image cf mode (1st FC port to fabric 1, 2nd to fabric 2); no V features used (back-end storage array connections)
Single initiator, single target zoning (Each ESXi hba port to one NetApp FC port per controller)
TROUBLESHOOTING (none of the steps below had any affect on pathing):
* Was happening with ESXi 5.0 with same DELL servers and NetApp controllers, and McData DS4700M FC SAN switches
* Built new ESXi 5.1 server on DELL R720
* Tried old firmware HBA QLE 2460 4.00.012 later upgraded to latest 5.09.0000
* Tried old firmware dual-port HBA QLE 2462 4.00.030 later upgraded to latest 5.09.0000
* Change FC fill-word option on Brocade switch ports from 1 to 3 for esxi ports and netapp ports
* Injected latest Qlogic drivers into ESXi OS (originally using v911.k1.1-26vmw but now 934.5.20.0-1vmw)
* Disable port features (NPIV, trunking, QoS) on Brocade for ESXi port
* Upgraded to ESXi 5.1 U1