We have a site collection specific term set with a custom sort order. Sometimes just after an IISRESET, the custom sort order is removed and the default alphabetical sort order is reverted to. I don't know specifically whether the IISRESET is the cause of this, especially as it does not always happen, but I can state that the very first action I perform after the IISRESET is to go to the homepage of my site collection, and by the time the homepage has rendered the custom sort order has been removed. I can see this because we use the termset to store the top navigation details (as SP 2013 would have us do) and the top navigation is in the wrong order. Furthermore if I go to the term store manager I see that the default sort order radio button is chosen "Use default sort order according to current language."
Any help would be appreciated.</label>