I noticed that as soon as NPCScan cached a rare I started getting d/ced every second. Deleted cache and now I can play for 15-30 min before a d/c.
I tested this again and when NPCScan cached a rare started getting d/ced again every second. Deleted cache folder and BAM back to 15-30 min before d/c.
Not sure if it's a coincidence or not. But thought I'd share.
EDIT: Correction: It seems to just be the cache in general. I started d/cing like crazy even without NPCScan detecting any rares. Deleted cache. Back to 15-30. So try deleting the cache every time you start d/cing too frequently.
EDIT #2: Must've been a giant coincidence. Deleting the cache no longer gives me periods of playtime.