Responding here to the entire thread.
We do have a bug in the SHP export in 18.104.22.168 indeed. More accurately, we have a bug and something that technically isn't a bug, but can also make SHPs unusable in other applications:
1. (Bug) Exporting objects sometimes produces geometry for just one object, typically the first. This is similar to what's reported in the first post. This is a straight regression coming from recent changes to SHP export that we did. We will fix it, the fix will be in the next cutting edge build.
2. (Not a bug, but...) We changed the way we export points and started marking them as multi-points, because points in 9 can potentially be multi-points. Multi-points are a valid type for a SHP file and they were part of the SHP file specification for a long time. However, as it turns out, while both 8 and 9 can read SHP files with multi-points just fine, other software (including ESRI products, amazingly enough) fails to do so and sometimes even crashes. We don't want to reduce multi-points to the first point during export (that's a data loss), nor do we want to split them into multiple records (that breaks uniqueness of the IDs), so that's a bit of a bind. What we decided to do is to use the file splitting capability that we already have in the SHP export and write points with a single coordinate as points as before, but write points with multiple coordinates as multi-points into a separate file. This way, if the user does not have any multi-points, he has no problems whatsoever, and if he does have multi-points and some software fails to read them, at least it is clear that the issue is related to multi-points. And if needs be, multi-points can be disassembled into simple points in 9 prior to the export.
Apologies for the issues.