Stuck without admin account on a MacBook Air running 10.5.8 I did a backup on my MacBook Air as I had lost admin rights and thought my best option was to carry out a reinstallation with the original disc which I obtain on purchase would assist.

When done, I loaded the updates etc, all was well until I restarted after some updates.

I lost admin rights so only had limited access as visitor, cannot go back to reload the software as keeps asking admin password.

Took my mac to BTOption supposedly Apple Authorized Service Provider (info@btoptions.com) in Colombo Sri Lanka, they are as stumped and as lost as I am, any suggestions greatly accepted.

They say I need the firmware password to reinstall the system.
Learned something new today:  You can break the firmware password with help from Apple.

http://reviews.cnet.com/8301-13727_7-57542601-263/efi-firmware-protection-locks-down-newer-macs/

This note says that Authorized Service Providers are equipped for that?  http://support.apple.com/kb/ts3554