I set up WordPress for a client on NetSol and was having issues getting plugins and themes to upgrade until I found this. I also followed the instructions to embed ftp access in the config file.
“Any time you use a “1 click install” with Network Solutions the files/folders are created with root level permissions. When you attempt to then remove the plugin you are only attempting to remove the plugin with the permissions granted by your FTP account. We have a script that fixes file permissions and restores them to FTP owner rather than root. Customer service can run this script, or you can run it from your control panel by clicking on nsHosting – Toolbox – then Reset File Permissions under the FTP and Content Publishing heading.
Dan’s correction to Michael’s original information is correct, localhost should be used as the hostname for upgrades to WordPress as well as installation of plugins etc when you are hosted with Network Solutions.”
http://wordpress.org/support/topic/network-solutions-plugin-upgrades-fail