Update Plugin Reports Success but Plugins Do Not Update

I am trying to update plugins through the dashboard. After selecting the plugins to update, wordpress reports that each plugin updates successfully. However, after going to the plugin screen, none of the updates were actually applied.

I do not have any issue updating wordpress, and manually updating the plugins through ftp is also not an issue.

None of the following troubleshooting steps have proved successful:
1) deactivating all plugins,
2) switching to the default theme, and
3) manually reinstalling 3.9.

Any help would be appreciated.