Playback issues on certain TV channels - possible codec issue?

[ctrlz]

I'm using the Argus TV addon to stream live TV to a couple of Venz V3 boxes, but having also used the MediaPortal addon I know this issue isn't specific to Argus TV.

I have a Windows client and Android TV client and they're fine. But on the Venz V3 (OpenElec) clients, on certain channels (e.g. "Watch" and "TLC" on Sky), the video playback is very jerky. It's not buffering and if I pause the stream for a while and then resume it the problem persists, plus other channels (including HD ones) are fine. So I know it's not a network bandwidth issue.

If I bring up the AV output stats and compare a working channel to a non-working one, they're identical except for this line:

WORKING:
D(Video: mpeg2video (Main) ([2][0][0][0] / 0x0002), yuv420p(tv),720x576 [SAR 16:15 DAR 4:3], max. 15000 kb/s)

NON-WORKING:
D(Video: mpeg2video (Main) ([2][0][0][0] / 0x0002), yuv420p(tv),720x576 [SAR 16:15 DAR 4:3], 10000 kb/s)

Notice the last part, which I believe is the audio bitrate? So all the working channels have "max. 15000 kb/s" and the non-working ones have something else. All the non-working ones I checked either had "10000 kb/s" or "9000 kb/s".

I tried changing the Output Configuration and Resample Quality in the audio settings but it didn't make any difference.

The codec in use is "am-mpeg2".

Any idea why this could be happening?

[ctrlz]

Any help with this?

[ctrlz]

Some support on this issue please?

I analysed the working and non-working streams in a bit more detail with a program called MediaInfo. The only differences between the two streams I can find are:

Working:
Max video bitrate: 15 Mbps
Audio bitrate: 224 kb/s
Format: GOP: M=3, N=24

Non-working:
Max video bitrate: 10000 kbps
Audio bitrate: 192 kb/s
Format: GOP: M=3, N=12

So it seems like some problem playing lower bitrate streams, which seems weird.