For those still experiencing the ringer bug, here's what I did:

Used that generic solution for any problem that arises to solve the ringer issue. I flashed back to Telus shipped. Hard reset. Flashed to Mighty 4.8. Hard reset. That solved that problem. I now can change the system and ringer volume all I like and still have the phone ring.

Caveat: Though now another problem arose. Copy and pasting text between opera browser and SMS does not work even with soft reset. Neither does choosing the option to "send text via SMS" from the pop-up menu work when in browser. Will try hard reset before reflashing straight to Mighty 4.8. If that doesn't work, then the I'll try the same solution for what I did for the ringer issue.