I was in the process of upgrading our workstations from 4.90 SP2 to 4.91
SP2. I completed about half of the 150 workstations when some users
notified me that they couldn't log into their workstations. They were
getting a message that their passwords were incorrect. This even
happened with the admin password. This happened on about 10
workstations. I reinstalled the client and it appeared to fix the
problem until the users shutdown the workstation, then it happened again.

I installed Patch C and it fixed the problem with incorrect password.
BUT, after installing that patch my users couldn't open MS-Access
databases because they got an error saying the file was locked by another
user. This happens when more than one user opens a database at the same
time. If they are the first user to open the database it's ok.

For these users to be able to log on the LAN and open databases, I had to
remove the client and install the older 4.90 sp2 client. I really don't
want to go back to an earlier client on all my workstations! Any help
would be greatly appreciated.