I just bought an entry level ibanez (Gsa60) from a friend and i'm having problems tuning it. Whenever i tune one string it detunes the others strings. So if i tune the first string to E then go to the second string and tune it to B the first string will be out of tune. The last owner told me that it was the strings, because they are old. I know new strings don't stay in tune well although i've never heard of old strings doing this also. It seems more like the string is pulling on something to detune the others or something like that...please help.
thanks.

-guitar Vomiter