I think the issue is with the One Click Plugin Updater (OCPU in future
to save my typing fingers). The next step, I'd suggest, is to manually
update this plugin. You may then find that things work fine with the
other plugin upgrades... if not, then one option would be to
deactivate and remove the OCPU and use the built-in WP functionality
for updating plugins. Does that make sense?
You will need to know your FTP details to enter when you upgrade
plugins via the built-in updater.
I am concerned about the security of any WP installation with OCPU as
it requires the plugins directory to be writeable by the webserver.
This means that if your WordPress installation was ever "broken into"
in any way, the miscreants would be able to do far more damage as they
could create new files, alter existing files and delete files within
the plugin directory. I'd recommend against using this plugin purely
because it opens up this potential for damage. WP has made great
strides with auto-updates in the built-in functionality, so you may
find it's (nearly) as easy to use that instead.
Hope this isn't all too alarming. :S
S