"most installed" sort ... isn't?

I noticed a couple of the distributions were apparently out of order, and after looking at all the numbers, there's quite a lot out of order. Here's the current usage numbers for the projects on http://drupal.org/project/distributions sorted by "most installed":

7030
1120
645
670
551
332
278
247
256
190
166
111
105
120
96
93
71
70
58
83
30
61
42
72
34

I thought this might just be a stale cache, but looking at the history on some of the discrepancies shows they were never actually in the order they're displayed. So apparently something else is wrong.