I would like to report the same issue's and add some of my information to this discussion.
Setup: 2x ltm 1600 in active/standby mode.
Firmware's 9.xx to 11.xx
I can confirm that the symptoms disappear when using a server or workstation with a single NIC or changing the load balancing from automatic to network Fail-over only.
To add. i have this issue with the VIP's but also with the self ip's of the LTM's.
Also the mgmt interface is hooked up to a seperate flat(no routing) L2 network with its own ip range.
Even the management interface's behave in the way's described in the above posts when accessed on a machine with double NIC's in the management network.
On servers with multiple NICS connected to 1 switch with port-aggregation / (lacp trunks) this issue does not occur.
I went trough all the possible arp tables and i cannot find any mismatch in the IP -> arp.
Regards,
Ton