Immanuel Velikovsky has long been discredited by plentiful evidence debunking his ideas. The only thing that can be said in his favour is that Carl Sagan apparently used some very dodgy methods to debunk V's claims, and that Velikovsky, through blind luck, got just 2 things right.

Here are  a couple of websites which point out Velikovsky's many  flaws:-

http://www.skepdic.com/velikov.html

http://abob.libs.uga.edu/bobk/vdtopten.html

At any rate, we can rest assured, from the above evidence,  that palaeolithic-era timelines are still accurate, despite V's claims.

Geoff.