Sorry for any frustration! This error is resolved for the original submitter, and these issues are not always an issue with the source, but the server environments in which it is ran.
It is very difficult and time consuming to know how a particular server could be configured. With thousands of different configuration possibilities its tough to know how PHP/Apache/Mysql is going to operate on thousands of different hosts. Throw in permissions, OSes, and all the various versions of WordPress and the test matrix is massive. This is why I rely heavily on the community and have a help ticket system if you want me to help you do a deeper dive on your system.
Most of these issues have to deal with how a host is configured and as I get feedback a vast majority of the issues are fixed. If I tried to make the plugin perfect for every hosting environment it would never get any releases. It is still in a beta stage...
Here are some suggestions for your particular issue:
You might try this suggestion for the file_get_contents warning. I'll see if I can route this to an fwrite, but my feeling is that the process under which PHP runs on your system may not have the correct elevation level to write to this file.
You can also try the "Developer Version" line found here as I'm continually making fixes as the community brings them in:
Just click on the "Developer Version" link and download the latest version. If you want an update of what is in it you can check the change log here.
If your still having issues please feel free submit a help ticket and I can work with you to find out what restrictions might be in effect on your server. 95% of the time its isolating how a server is setup and permission issues.
Hope that help!