I don't think the PM system is fundamentally broken.
It appears that SMF can't make up its mind about whether to represent a single quote in a name as
',
], or
]. The database held the second but the name matcher when sending a PM appear to be looking for the third.
It appears the only people affected were me and Jack O'Ferrall.
This is exactly why I tell developers to store the raw form of the data instead of guessing where it's going to be used and pre-encoding it.
As for the import failure, I'll look at it if somebody can upload the relevant output files to the replays site.