http://mirror.centos.org/centos/5/isos/
There is a live CentOS 5.4 cd too.
+ a very small netinstall iso : only 8.9 MB,
which of course will behave very different from the live cd.
And by the way, I had no problems with the live
Scientific SL 53, may be they changed something,
or your copy isn't perfect ?
.....