Any max number or records in CB?

Is there a maximum number of records that can be handled in CB?

I have a list of 90,000 that I'm uploading via CBJuice. I've split the list into 90 files of about 1,000 each so as not to kill the server. They all seem to load properly, but...

When all 90 files have been uploaded (and we have done all of them 2 times just to confirm), the total number of records in CB is around 51,000.

Just to make it a bit more complex, I also have Acymailing's CBplugin that duplicates the CB records to Acymailing. I do get the same number of records in both CB and Acy.

Is there an obvious answer here that I'm missing?

Database rows typically has no limit, we've over 400,000 in ours. My best guess is some of those rows didn't import properly. Maybe some user imports have missing or incorrect data.