I have always had problems with Mandrake thinking I have a nicer computer than I should. Mandrake is maybe one of the only distributions which should have minimum system requirements. You may want to try an older version like 7.0 as they havent changed much except for some weird Mandrake specific things(and the serious changes can always be updated ie kernel).
If it is not too much trouble try one of the older Mandrakes. I would hate to to see you give up because you had install trouble(lord knows I have had enough of that in windoze)
Anyways, give it a chanc eand you will be pleasantlty surprised