OSX Lion File Sharing to Ubuntu

Hi folks. I've spent quite a bit of time trying to resolve this issue to no avail. If anyone has a workaround I would appreciate it. Here's the problem:

SMB in Lion is not the same as it was under SL. This is a problem on a home network that uses three different operating systems. The Windows machines have no issue with accessing files hosted on the Lion machine. However, my primary laptop runs Ubuntu 11.04 and can only copy files from the Lion machine. I need to be able to write to them. I have checked permissions and they appear valid.

As I hinted to, I'm at my wits' end on this and could find no assistance on Linux forums. I cannot be the only one with this issue. Any suggestions would be welcome. Thank you in advance.

I'm surprised an issue with this hasn't come up earlier since the underlying framework for SMB sharing has changed completely (you can blame the GPL v3 for the exclusion of Samba).

Are you authenticating as a user with write privileges from Ubuntu? Are you saying that you appear to have write privileges from your Ubuntu machine?

I am able to connect using the credentials of the OSX machine. At that point I can mount and copy just not write. I've tried to add a new user for sharing purposes to the OSX accounts and when I try to select that account for sharing via SMB the password is incorrect (God only knows why. It's the same pw I used to create it). Since the accounted logged in on the OSX machine is already setup with read/write privileges, it was easier to use those credentials. Again, I can mount and read this way, just not write. And I have verified that all privileges are applied to all sub-directories.

Thanks for the help, btw.