hd sometimes 'hangs' a few seconds

[Hans Schippers <saintiss gmx net>]

hi,

I recently changed my filesystem to ext3 (from ext2), and since then, my hard 
disk sometimes seems to 'hang' a few seconds (in fact the whole system hangs 
then, and only the hd LED is on), before continuing normally... This happens 
for example (not always though) when I untar an archive and try to ls in the 
newly created directory...

Is there an explanation for this? 

And if so, what's the best solution? 
(I'm running RH 7.1.94 (roswell))

Sincerely

Hans Schippers