[Koha] a few koha errors

[zero at vtr.net]

Hi all, 2.2 is out and i'm testing it, but got errors (well got them since
2.0.0) when I try to add a new biblio get an error just after pressing OK.
Also get another one after adding a member (same thing) but this time the
member is succesfully added anyway. But changing setting I don't get any
errors seems only when adding stuff. 
How do I make the error be displayed on browser?

I'm also viewing the koha-error_log  and found very interesting things....
It claims for a favicon.ico   (man what the heek is taht?)  and the always
spected Premature end of scripts headers. And a few others like ERROR: Date::Manip
unable to determine TimeZone.,
Can't use an undefined value as a HASH reference at /usr/local/koha/intranet/modules/C4/AuthoritiesMarc.pm
line 76.,

Ok i'm only asking for a few poniters.  I've installed it succesfully, with
all the modules in Linux FC3.
Hope someone could help...

Cheers  bye...

jose