[Samba] samba log filled with Invalid vuid message

[Emilio Casbas]

Today, in only a few hours, the samba log file has been filled (up to 
10G!) with this message;

[2006/06/15 16:48:24, 2] smbd/uid.c:change_to_user(247)
  change_to_user: Invalid vuid used 100 in accessing share disco5.

Our current samba version is samba-3.0.21c, and it has been running
without any problem for a month.

Any ideas about what happened?

Thanks in advance.
Emilio C.