matt has listed the answer to this several times. in addition, if i recall, it's noted in the extensions.conf file. you can strip the first digit off inbound calls from your provider, thus sending the 10 digit actual phone to vicidial instead of the 11 digit phone_code+phone_number.
you can also request your provider send only 10 digits for the inbound caller id, but that can sometimes lead to a six month discussion as the technical support at some providers is ... not as good as it could be. generally easier to just remove the leading 1 yourself.
also, please note that 2.0.5 is no longer officially supported (and upgrading to 2.2.X via SVN is only a few lines of code ...
)