I have a problem. I have

Phone: SGS3
Android: 4.3
iGO: iGO_9.6.29.390522+HD
TTS Engine installed: Samsung, Google, Loquendo
TTS Engine Selected: Loquendo
voice folder content:
Voice_Eng-us-f1-lua.zip
Voice_TTS-Loquendo7-Pro-UK-Kate-zervdim-V7.1.zip (I don't think this is being used)
Voice_TTS-Loquendo7-Pro-UK-Simon-zervdim-V7.1.zip (I don't think this is being used)
Voice_TTS-Pro-English-US-loquendo7-Android-zervdim-V4.zip
lang folder content:
Lang_English-uk.zip
Lang_English-us.zip

Problem description:

When I have the Loquendo TTS voice selected in iGO, I can no longer access the Voice volume/ mute menu. I need to select the non-TTS voice, change my voice volume/ mute/ unmute, then revert to the other voice. Any suggestions?

I have screenshots showing the effect.

TTS voice selected:
[Only registered and activated users can see links. ]

Volume menu is missing some items:
[Only registered and activated users can see links. ]

After selecting non-TTS voice:
[Only registered and activated users can see links. ]

The volume menu has a voice volume button and slider:
[Only registered and activated users can see links. ]