Cache question/bug report?

[jda]

In my V4RB-based app, I have a rebuild option. All records are 
written to disk (in my own format), a new database is created, and 
the records are imported into that. It's much, much faster than 
export/import as XML and generally works well.

But now two different users have complained that their large database 
fail. The export/import goes well and the database seems fine. You 
can search, sort, etc.

BUT, once you close the db, if you try to reopen you get a -39 error.

I have one of these dbs and can reproduce the problem. It has about 
3200 records (mostly text and blob) with LOTS of data (the db is 
about 23 MB).

After a lot of playing around, I find that if I increase the 
Valentina db cache to 50 MB (up from my standard of 20 MB) 
export/import now works!

Why might this be? Doesn't Valentina page out when the cache is filled?

This is on OS X, if that makes any difference.

Thanks,

Jon