1. Hwh-R=> GNWL
Check for Bilaspur, Durg and other major stations where the train halts for 5 mins or more. You would find the same status for most of them as that to HWH-CSTM.
In such cases some of the stations has been given an individual quota of its own. When this individual quota gets exhausted, the WL directly moves to the common GNWL maintained for HWH-CSTM.
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example check for HWH-BSP for 20/21 October, 2011 and match the other dates with HWH-CSTM.

When the quota of these intermediate station gets exhausted and directly moves to GNWL, one needs to be careful while purchasing these tickets. If I book a waitlisted ticket from HWH-R, some other passenger might or might not book for R-CSTM or any other station enroute. In such cases, the system would prefer to allocate any vacant berth who would travel all the way through.
For example: HWH-R=> WL 1
HWH-CSTM => WL 2
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is no waitlisted passenger for R-CSTM. Thus WL 2 would be confirmed and WL 1 would not. This is precisely why you would find passengers often complaining that a person having waitlisted status more than me got confirmed.
Alternate:-
HWH-CSTM=> WL 1
HWH-R=> WL 2
R-CSTM=> WL 3
1. Now if a confirmed passenger for HWH-R cancels the ticket then WL 2 would get preference. In such cases WL 1 and WL 3 would remain as it is.
2. If case 1 happens, plus if a confirmed passenger from R-CSTM cancels his ticket, both WL 2 and WL 3 now gets confirmed. WL 1 remains as it is.