Access privileges troubles while using STSADM

Being promoted to MOSS Farm administrator in Central Administration Application still doesn't mean one may freely use also STSADM utility on this farm.
Promotion to farm administrator registers a user for use MOSS config database but not the Admin Content database. You need access to Admin Content database to be able to use STSADM - at least dbdatareader and dbdatawriter role.

Unfortunately, there are number of operations not available from Central Administration, but highly required to perform effective farm administration. One sample is adding a MOSS solution to the farm: you cannot do it from CA - only STSADM -o addsolution helps.

So, as far as you consider to use STSADM utility to manage your farm - be sure you have enough privileges for MOSS SQL database.

Enjoy!