[Dovecot] dsync: mbox to maildir hangs

[Burckhard Schmidt]

Hello,

after successfully converting some mailboxes I have a problem:
dsync does not finish its work.

dovecot 2.0.2.
mail-location maildir:~/maildir

I have copied the old Inbox and folders into /mailstore1/import-inbox 
and /mailstore1/import-home to the new server. (used with Dovecot 1.0.13 
before)

For one account I have now 356 folders containing about 60000 emails.
(35 folders with about 40000 emails had been converted without problems)

I used:
dsync -v -u account mirror 
mbox:/mailstore1/import-home/~account:INBOX=/mailstore1/import-inbox/account 


dsync shoes after two minutes a list of all folders like this
dsync(account): Info: Mail/folderx: only in dest

After about 8 minutes some folders are converted.
But then it hangs inside a folder which is just converting.
I see entries (emails) inside "folder/tmp" but not all. And the
"folder/cur" is still empty.

dsync uses about 75% of one cpu all the time. I was waiting more than 50 
minutes but no progress.
I have to use kill -9 to stop it.
If I delete this folder it still happens with a different one.

Are there any limitations?
Any advice?

Regards - Burckhard Schmidt