Problem upgrading to 10.04

[nandinibhaduri]

I am using 9.10 and wanted to upgrade to 10.04 using Update Manager - for the step - getting new packages - I am getting the following error -

Failed to fetch http://ubuntu-archive.sit.kmutt.ac.th/pool/universe/f/festlex-cmu/festlex-cmu_1.4.0-6_all.deb 403 Forbidden
Failed to fetch http://ubuntu-archive.sit.kmutt.ac.th/pool/universe/f/festlex-poslex/festlex-poslex_1.4.0-5_all.deb 403 Forbidden
Failed to fetch http://ubuntu-archive.sit.kmutt.ac.th/pool/universe/g/gtkglext/libgtkglext1_1.2.0-1ubuntu1_i386.deb 403 Forbidden
Failed to fetch http://ubuntu-archive.sit.kmutt.ac.th/pool/universe/f/festvox-kallpc16k/festvox-kallpc16k_1.4.0-5_all.deb 403 Forbidden

I tried 2-3 times and got the same error. Can anyone help?

[nandinibhaduri]

Changed the Source from System -> Administration -> Source List - and the upgrade went fine. Lucid Lynx look great.:p