Account sometimes not displayed on Reboot

[cpragman]

Strange intermittent problem here.... System is 10.7.4. I have an administrator account. The contents of which were migrated from my older machine (OS 10.5.x). Has been working fine since I migrated to this new mac in January, except that occasionally, my account isn't displayed as one of the choices at the Login Window. The other accounts on the machine are still displayed (wife's, kid's, my extra admin account, etc.). Just my everyday admin account won't display.

Rebooting seems to eventually fix the problem (not always the first reboot). And Disk Utility reports no problems.

If this is trying to tell me that there is something partially corrupt with my account or settings, I'd like to fix it, in case whatever is wrong is fragile and gets worse.

I see some log entries that might be relevant, but not sure where to look next:

7/5/12 5:04:40.224 PM SecurityAgent: User info context values set for my_id
7/5/12 5:04:40.224 PM SecurityAgent: User info context values set for my_id
7/5/12 5:04:40.622 PM authorizationhost: Failed to authenticate user <my_id> (error: 9).
7/5/12 5:04:43.319 PM SecurityAgent: User info context values set for my_id
7/5/12 5:04:43.319 PM SecurityAgent: User info context values set for my_id
7/5/12 5:04:45.029 PM SecurityAgent: Login Window login proceeding
7/5/12 5:04:45.029 PM SecurityAgent: Login Window login proceeding
7/5/12 5:04:45.411 PM loginwindow: Login Window - Returned from Security Agent
7/5/12 5:04:45.417 PM loginwindow: USER_PROCESS: 41 console
7/5/12 5:04:45.419 PM corestoraged: 0x7fff7a657960 unlockLVF: LVF=EAA4BEF2-ED7C-49CB-A0FA-AB5A64109ED4, "AES-XTS", status = "Locked"