If two mods with the NoMerge tag touch the same record subsequent changes later in the load order to the same record are getting ignored by CBash.
More details including full load order, bash tags, etc can be found at: http://forums.bethsoft.com/topic/1411667-relz-wrye-bash-thread-95/page__view__findpost__p__21549282
Subsequent posts by others confirm the bug.
Here are two specific examples.
First example: http://oblivion.nexu...-1346975696.jpg
OMOBS_SI.esp is higher in the load order than FCOM_Archery.esp. Both mods have the {Nomerge,Stats} tags.
When building the Patch with Python, the damage is correctly getting imported from FCOM_Archery.esp, but when building with CBash it appears FCOM_Archery.esp is getting ignored and the damage from OMOBS is getting imported instead. Based on what I'm seeing this is happening with arrows touched by both OMOBS and FCOM_Archery. However, if FCOM_Archery touches something that OMOBS doesn't, then the FCOM_Archery damage does get imported. CBash is only looking at the first mod with {NoMerge,Stats} in the load order and ignoring subsequent changes. Similar behavior occurs with bows.
Second example: http://oblivion.nexu...-1347631990.jpg
1em_Vilja MMM FCOM Fix.esp has the {NoMerge, Factions, Relations} tags, followed by 1em_Vilja_as_Custom_by_Gonzoguns.esp which is a merged patch, followed by 1em_ViljaCool77g.esp which has the {Hair, NoMerge, Npc.HairOnly} tags.
1em_ViljaCool77g.esp is last in the load order, and when building the Bashed Patch with Python the hair colors get imported into the Bashed Patch. However, when building with CBash it gets ignored.
Now, things get really interesting - if I uncheck 1em_Vilja MMM FCOM Fix.esp under both Factions and Relations when building with Cbash, then rebuild the Bashed Patch with Cbash, then the hair color from 1em_ViljaCool77g.esp does get imported. What's interesting in this case is that the two mods with NoMerge both touch the same NPC record, but they are supposed to be importing different subrecords.
Looks like the links to the screenshots got truncated when cutting and pasting from the Bethesda forum, so I'm reposting those links.
Here's the first example: http://oblivion.nexusmods.com/images/109590-1346975696.jpg
Here's the second: http://oblivion.nexusmods.com/images/109590-1347631990.jpg
Closed - Moved to github https://github.com/wrye-bash/wrye-bash/issues/487