CD to MIME Conversion Error: “CVS: Failure”

After upgrading a customer server from 6.5.4 to 7.0.1 I am having major issues with CD to MIME conversion in e-mails sent via LotusScript (normal e-mail sending is OK):

14-03-2006 13:44:55   Begin CD to MIME Conversion(Process: Router (000008CC:0000000D), Database: E:DominoDatamail.box, Note: 00305AEE)
14-03-2006 13:44:55   CD to MIME error (Process: Router (000008CC:0000000D), Database: E:DominoDatamail.box, Note: 00305AEE): CVS: Failure
14-03-2006 13:44:55   End CD to MIME Conversion(Process: Router (000008CC:0000000D), Database: E:DominoDatamail.box, Note: 00305AEE)
14-03-2006 13:44:55   Router: No messages transferred to 192.2.4.9 (host 192.2.4.9) via SMTP

I tried enabling debugging for the conversion process using some notes.ini settings (CONVERTER_LOG_LEVEL=40, DebugMIMEConversion=1) but they doesn’t provide anything useful.

Anyone with ideas? I’m currently downloading Domino 7.0 to see if downgrading will help.