对于登陆不了的。如果上面显示：Maximum number of sessions for this account has been reached. You are already logged in on another computer. Click here to force closure of other sessions 点击：Click here to force closure of other sessions再登陆就可以进入了。已经在里面的用户不会被强行关闭。
关于看不到上传工具的问题还在研究中。
我写信个他们的技术支持。他们回的信是：
I ask that you clear your browsers cache and try again.
但是我不知道什么是browsers cache，偶把能删的都删了，还是看不到上传工具。
This tool requires Java.
If you do not see an upload tool, please make sure your browser has Java turned on.
This tool will upload directories. Simply select a directory and it's contents will show in the list. Each file will show the directory tree that file is in. Example: foo/bar.txt will be uploaded to a folder "foo" in the current server directory. If you haven't already created that directory on the server, this tool will create it for you.
You can drag and drop files onto the applet to add them to the upload list or you can use the add button to browse your files.
Some virus protection software 'proxies' the connection and will show the upload as 100% done even though the proxy is still sending the data to the server. Please be patient and let it run. It will refresh when it is completed.
楼主 
