Please ensure you are running the latest HIP 7 patch 7 which is version 18.104.22.1682.
Also please ensure you are running the latestdriver version for your network adapter(s).
I would enable full debug logging for HIP per KB51517.
Reboot and monitor.
If the issue occurs again, open task mgr and note if it appeared to be memory relelated. Generally if the server is resolnsive otherwise, it would not be related to a memory leak (though you did not provide any other details).
Note if any process seems to be hung or consuming excessive cpu while in that state.
Run the HIP WebMER to collect all of the logs, then open a support case.
I believe it may have been a combination of issues. We were using the ESX ver 3.5 on the physical server to manage our VM environment and discussions among other VM architects reveal similar issues. It was determined that when they upgraded to ESX ver 4.0 the issue resolved itself. It also appeared this issue was originally addressed within the SP 6 of HIPS regarding the partial install glitch of the firehk. After I recreate the scenario in a test lab I will report back if it was simply upgrading to ver of ver 4.0 or if it required a repatch of SP6 (or 7) to correct the issue.