dsync with namespaces

I have a major dsync headache which I am hoping someone can help me with.

I have to migrate mails from a 'namespace/inbox/prefix=INBOX.' server to a 'namespace/inbox/prefix=' server.

So I'm trying # dsync -o 'namespace/inbox/prefix=' sync -1 -f -u xx@xx.com tcp:1.2.3.4

It works fine for some accounts, however for others many hundreds and sometimes thousands of mails go missing from the destination inbox, and a resync doesn't pick them up. The debug output doesn't recognize these either.

If I remove the 'namespace/inbox/prefix=' part, then I get 'Error: Couldn't find namespace for mailbox X' errors.

Both source and destination is running 2.2.27

I can't imapsync :S

Thanks.

Tom