i use the Plugin Updates plugin.
sometimes, not very often, if i check for new versions, i got:
Warning: fread(): supplied argument is not a valid stream resource in
/..../plugins/pupdate/update.php on line 280
i got this with sm 1.4.3a and sm 1.5.1cvs.
don't know why or which plugin causes the problem.
all plugins are showed in the list.