[Tex/LaTex] Command \AtBeginEnvironment already defined

datatoolerrorsetoolboxtexmakerUbuntu

I am pretty new to LaTeX. With windows, Miktex/Texmaker pretty-much takes care of package installation whenever needed, but on Ubuntu I have been downloading needed packages from CTAN and installing them manually. So today I installed three packages on my Ubuntu 9.10: xfor, datatool and etoolbox. For some reason I get this weird error on quick build:

(/usr/share/texmf/tex/latex/datatool/datatool-base.sty
Package: datatool-base 2012/07/18 v2.10 (NLCT)
(/usr/share/texmf/tex/latex/etoolbox/etoolbox.sty
Package: etoolbox 2011/01/03 v2.1 e-TeX tools for LaTeX
\etb@tempcnta=\count97
! LaTeX Error: Command \AtBeginEnvironment already defined.
Or name \end... illegal, see p.192 of the manual.
See the LaTeX manual or LaTeX Companion for explanation.
Type H <return> for immediate help.
...

Can anyone help me fix this error ? I am actually writing my thesis using a cls file provided by my university. I am using Texmaker editor.

Best Answer

the problem is the etextools package, that contains many names that can easily lead to clashes, like discussed here: Re: The package 'etextools' is not compatible with biblatex