Can't Send Attachments: LZ1 Encoding Failure

Client running 6.5.4 on Macintosh. Attempts to send notes with attachments fail with dialogue box “LZ1 Encoding failure. Mail.box” (OK button).

Happens most often with MS-Word or .ppt attachments, but .pdfs fail occasionally as well. Not consistent from day to day. This is using a local mailbox file. This is a message from Notes, not from the Domino server.

Completely removed and reinstalled Notes 6.5.4 from master image, including removing all preference files from HD. Notes runs fine, receives attached files just fine … sending is only problem.

MacOS 10.4.8, Mac Office 11.3, G4 Powerbook 1.67GHz, 80GB HD and 1.5GB memory.

Unless someone has a better idea, will next reinstall Office … after that, reinstall the OS.