BB Storm 9500 :: Intern OS 5.0.0.451 Ringer Sound Gone & Keypad Tones Gone

I have recently updated to the new OS via desktop manager. Shortly afterwards i have noticed missing calls and messages. The vibrate alert works & the light flashes but no sounds. I have expeirienced a similar but different issue on the last update, where all ringtones and sounds were ereased from the phone, resolution was go back to previous update and re apply update.

After a number of battery out reboots i have unfortunately not had success in correcting the fault. I note that the keypad tones are also gone when attempting to make a call. I have tried playing audio files and have no sound unless i switch to speakerphone, have considered that perhaps the speaker has failed or the issue has disabled the main speaker, guessing the ringer would use this...the phone works fine i.e the speaker next to ear works o.k but no evidence of any audio from the one on the back. In my few hours of exploring and proding the device i have discovered that the mute button seems to not do anything...

Can anyone offer some guidance or suggest a solution. I have trawled the forum a bit and found similar but not same descriptions, have explored all suggestions but have come up short