VCA cannot contact VCRM after upgrade of SMH on VCRM

Hi,

HP SIM 7.1.0 on Win2008 R2

Hotfixes up to HOTFIX71_027 applied

I recently upgraded the System Management Homepage on my VCRM from 7.1.2.3 to 7.3.2.1 (because of the heartbleed vulnerability) and all my VCA's on my Windows servers could no longer communicate with the VCRM.  As soon as I reverted back to the original version, communication began to work again.

Does anybody know of why this may be?  I'm wondering if it may be something to do with a trust?

Thanks in advance,

John