tomboy: command not found

Have You tried accessing the binary with the full path?

Maybe Your $PATH variable doesn't contain the default paths? echo $PATH should give something like:

[root@server ~]# echo $PATH
/usr/local/sbin:/usr/local/bin:/sbin:/bin:/usr/sbin:/usr/bin:/root/bin

If it's empty, You may set the PATH variable with this command

export PATH="/usr/local/sbin:/usr/local/bin:/sbin:/bin:/usr/sbin:/usr/bin:/root/bin"

On Debian possible default full paths are:

/usr/bin/tomboy - from package: tomboy

You may install the required package with command apt-get install {package}
Error in other languages:
tomboy: bevel nie gevind nie
tomboy: comandă negăsită
tomboy: comando não encontrado
tomboy: commande introuvable
tomboy: command not found
tomboy: käsku ei ole
tomboy: không tìm thấy lệnh
tomboy: komanda nerasta
tomboy: Kommando nicht gefunden.
tomboy: kommandot finns inte
tomboy: komut yok
tomboy: nie znaleziono polecenia
tomboy: níor aimsíodh an t-ordú
tomboy: no se encontró la orden
tomboy: no s'ha trobat l'ordre
tomboy: opdracht niet gevonden
tomboy: parancs nem található
tomboy: perintah tidak ditemukan
tomboy: príkaz nenájdený
tomboy: příkaz nenalezen
tomboy: команда не найдена
tomboy: командата не е открита
tomboy: 命令找不到
tomboy: コマンドが見つかりません