problem with fonts when using root-tail

[M. Fioretti]

Greetings,

I run into the following error when running root-tail (*) on a Fedora 14 x86_64 system:

root-tail -g 800x250+100+50  /var/log/messages,green -font 12x24 /var/log/secure,red,'ALERT' 
Missing charsets in String to FontSet conversion (ISO8859-7)
Missing charsets in String to FontSet conversion (ISO8859-1)
unable to create fontset for font '12x24', exiting.

I've already searched online a bit, but didn't find any info as to
which other packages I should install, or what else I should
read/check to get more info and fix this problem. Any pointer is
appreciated!

TIA,
    		Marco
(*) http://oldhome.schmorp.de/marc/root-tail.html