I have the Chromecast with Google TV and the IR volume control of my Sony 1080 receiver is flaky, to say the least. It rarely works, and when it does, usually just alters the violent by 1 increment. Doesn't matter if you press and hold or press repeatedly, nor does it matter how you aim the IR hole or distance from receiver.
Google support had me reset the entire CwGTV unit, and that worked for a few days, but then back to flaky. I've retrained the remote many times, but that didn't help.
The receiver remote changes volume fine, as does my samsung tv remote.
Any ideas?
I had a similar issue.
I just went through the pairing/syncing procedure and made sure it synced to the device and not just through CEC and it’s been working better since.