I hit a snag the other day when posting comments to a few of my blogs. It told me that I was abusing my own blog. Perhaps you've had a similar experience on this or the R3 Frontline blog?
Earlier in September, I had to tighten up the blog software a little. It's possible that I went too far and that it's too restrictive. But, you need to tell me if this is the case, because I don't have time to look over the logs.
In general, the abuse detection algorithm scores your comments based on:
If the combined score exceeds the limit, then you'll see that abuse message.
Let me know if I need to make adjustments.