Another wierd error whilst installing gems?

what could cause this error in terminal when updating gems?

Bulk updating Gem source index for: http://gems.rubyforge.org
ERROR: While executing gem … (Errno::EACCES)
Permission denied -
/usr/lib/ruby/gems/1.8/cache/rb-appscript-0.3.0.gem
[marcrice:~] marcrice%

please help!

libsfan01 wrote:

Well, going by the “permission denied” message I’d guess that you don’t
have the access rights to the directory. On my Linux box, at least, I
have to have root authority to modify anything in /usr. Perhaps you need
to log on as root or use sudo when you execute the gem command?