Link Aggregate Group (LAG.) A LAG cannot span multiple Virtual Connect modules

 Link Aggregate Group (LAG.) A LAG cannot span multiple Virtual Connect modules.

By adding multiple uplink ports from the same I/O module, and the Connection Mode is
set to Auto, Virtual Connect will attempt to form a LACP (802.3ad) Link Aggregate
Group (LAG.) A LAG cannot span multiple Virtual Connect modules. Changing the
Connection Mode to Failover will prohibit Virtual Connect from forming a LAG. The
upstream switch must have its 802.3ad configuration mode set to On.

HP BladeSystem Interconnect - HP Virtual Connect Flex-10 Module: Internal Stacking Link X7 or X8 Will Be Disabled when You Insert a SFP+ Module

HP BladeSystem Interconnect - HP Virtual Connect Flex-10 Module: Internal Stacking Link X7 or X8 Will Be Disabled when You Insert a SFP+ Module


Information
Port X7 and port X8 is internally cross linked to an adjacent HP Virtual Connect Flex-10 module. This connection is used a Stacking link (Virtual Connect Flex-10 bay 1, port X7 - Virtual Connect Flex-10 bay 2, port X7 and Virtual Connect Flex-10 bay 1, port X8 - Virtual Connect Flex-10 bay 2, port X8 ) between the Virtual Connect Flex-10 interconnects.
Port X7 and port X8 can also be used to connect to an external network switch. The moment an external SFP+ module is inserted in port X7 or port X8 , the internal stacking link (Virtual Connect Flex-10 bay 1, port X7 - Virtual Connect Flex-10 bay 2, port X7 , or Virtual Connect Flex-10 bay 1, port X8 - Virtual Connect Flex-10 bay 2, port X8 ) is disabled and not visible anymore as Stacking link within Virtual Connect Manager (VCM)
Details

This is working as designed.
Source:  http://h20000.www2.hp.com/bizsupport/TechSupport/Document.jsp?lang=en&cc=us&taskId=120&prodSeriesId=3794423&prodTypeId=329290&objectID=c01677930

HP Gen8 Servers NICs & vSphere Compatibility Matrix

Here is the HP Gen8 Servers NICs and vSphere 4.x / 5.x Compatibility Matrix

Make	Model	Ports	Speed	Format	ESXi 4.1	ESXi 4.1 U1	ESXi 4.1 U2	ESXi 5.0	ESXi 5.0 U1
HP	FlexFabric 10Gb 2-port 554FLB FlexLOM Adapter	2	10 Gb	Flex-LOM	Yes	Yes	Yes	Yes	Yes
HP	FlexFabric 10Gb 2-Port 554M Adapter	2	10 Gb	Mezzanine	No	No	No	No	No
HP	Flex-10 10Gb 2-Port 530M Adapter	2	10 Gb	Mezzanine	No	No	No	No	No
HP	Flex-10 10Gb 2-Port 552M Adapter	2	10 Gb	Mezzanine	Yes	Yes	Yes	Yes	Yes