[texhax] issues with the tabu package

[jtzzaa11-texhax1 at yahoo.com]

Hello,

I've come across two issues with the tabu package version 2.8, and would appreciate help from the ML members:

1. I've defined the new commands 
\newcommand{\btabu}{\begin{tabu}}
\newcommand{\etabu}{\end{tabu}}

but this minimal example 

\documentclass[10pt]{article}

\usepackage{tabu}
\usepackage{colortbl}

\begin{document}

\newcommand{\btabu}{\begin{tabu}}
\newcommand{\etabu}{\end{tabu}}

\btabu{ l l }
1 & 2    \\
a & b     \\    
\etabu

\end{document}

returns the error:
! Missing $ inserted.
<inserted text> 
                $
l.16 \end{document}

changing \etabu to \end{tabu} removes the error.

2. The tabularborder package clashes with tabu and colortbl. here's a minimal example:

\documentclass[10pt]{article}

\usepackage{tabu}
\usepackage{colortbl}
\usepackage{tabularborder}

\begin{document}

\newcommand{\btabu}{\begin{tabu}}
\newcommand{\etabu}{\end{tabu}}

\begin{tabu}{ l l }
1 & 2    \\
a & b     \\    
\end{tabu}

\end{document}

which gives the error:
! Undefined control sequence.
<template> ... at setup \CT at row@color \CT at cell@color 
                                                  \CT at do@color \endgroup \@t...
l.15 \end{tabu}

Any suggestions how to solve this?

TIA,
Joel