Header Download Issue?

[TBlack]

I automatically download 10 groups. I can see great download speed and header compression on the first 8 or 9 groups. The last group (and sometimes the last two groups) most often drops to a snail's pace (drops down to 2 - 4 Mbps). Here's the thing.....if I delete the last one or two very slow groups from the download area and then immediately re-download that same group or groups, download speed and header compression seems to be restored and perfect and the download completes just fine.

What I'm seeing is repeatable so thought I would report.