"Sort by" on search result page 500 error, and some redirect to homepage

[nflmerch]

J1.7.2 and VM2 subrelease K

If I use the Search function:
and when I'm on the search results page, Sort By: Manufacturer gives me a 500 error.
Also,  Sort by: SKU, product name, and category all redirect me to the shop homepage.

If I select a Category:
the "Sort by" seems to work as expected.  However,  Sort by: Manufacturer has a little language file problem, because the dropdown then reads as "COM_VIRTUEMART_SEARCH_ORDER_MANUFACTURER"

[nflmerch]

As of subrelease M,  the "sort by" dropdown still has very strange behavior. 

There's some slightly different behavior than my last post from subrelease K, but it still has undesired behavior and the "Sort By: Manufacturer" still produces a server error.
Thank you