perl-mode line-number

perl-mode line-number

[Johan Meskens CS3 jmcs3]

hello

in perl-mode i have the line-number feature on
  - the beginning of every line has the actual line number -

now when i copy/paste code
   the line-numbering gets messed up
   , the first line of the pasted code gets a line-number
     the rest doesn't

when i close that file
and reopen it
  , the line-numbering is as it should be

is there a way - apart from closing/opening file -
to readjust the numbering while working ?

thanks
jmcs3