Keychain Problems

[BobGir]

    Info on my setup first:

Dual-USB iBook
640MB of Ram
OS 10.3.4
Airport Base Station M5757 (Graphite)
Airport Card 8.2001
Linksys BEFSR41 Router, v.3

    Here's the problem.  Every one or two days, when I try to empty the
trash, or use Safari to access a site which requires a password, etc., I
can't do it.  I get an alert box instead.

    When this happens, I launch Keychain Access and, instead of being
presented with my Keychain, I am presented with a "New Keychain" dialog box.
When I click on Create, I get another alert: An error occurred while
creating a new keychain.

    Run Keychain First Aid, and I get >verification failed, restart your
machine.  If this doesn't work, you may need to reinstall the system
software.<  A restart usually always does the trick.

    If I run Repair in Keychain First Aid, I get >repair failed<.

    I've reinstalled the system software once already.  I don't want to keep
having to do this, but I can't seem to arrive at a durable solution.

    Can anyone suggest a permanent fix for this???

    Many thanks,
    bob