Troubles in a multiple choice

Hi and good evening to all!

I'm having a trouble with a multiple choice:

I've added, taking looks at various files, some lines of code like these:

comment 'Choose your timezone'
    choice ROCKCFG_PKG_GLIBC_TIMEZONE `(grep "$1/"
/usr/share/zoneinfo/zone.tab | cut -f3 | sort -u | tr '\n' ' ')

but it puts an entry in a text box and on the same line it adds an extra
entry like an "echo <text>" and scrolling the choice list various
entries are missing... (exactly it puts the first entry of the list like
the "echo <text>" and the second in the text box...)

How someone could solve my little problem... (probably silly but I'm
trying to manage it from an hour...)

Good evening and thanks in advance,
Luca