Creating squat index fails for a specific folder

[Jörg Spilker]

Hello,

indexing messsages with squatter fails for one folder:

Indexing mailboxuser.js.Mailinglisten.Geheim... Indexed 97 messages (670887 bytes) into 479412 index bytes in 1 seconds
error opening user.js.Mailinglisten.Geheim default: Unknown/invalid partition
Total over all mailboxes: Indexed 67765 messages (414813852 bytes) into 259510744 index bytes in 792 seconds

Even a reconstruct -r user.js.Mailinglisten.Geheim doesn´t solve the problem
(Geheim itself contains some messages and has two more submailboxes).  

Accessing the above mailbox and submailboxes with an imap client however is not a problem.

How can i solve the problem (as squatter stops indexing after the first error, i can´t index my
folders completely).

Greeting, Joerg