things like modifying the web.config file will restart the application, but mojoportal application code does not restart the application.
frequent application restarts are a symptom of a low memory environment. hosts can and often do put a memory limit on the application pool and when it reaches that limit it will restart the application. in a low memory allocation it will reach the limit right away and this causes it to restart over and over
I have no idea why this would start happening after the site has been running fine for a long time unless the host recently lowered the memory limit or some unknown factor causing it to use more memory than before