G'day ruba11,
I have not looked at your problem in detail, but have you applied my patch above? It sounds like this might resolve it.
I see that it has still not been added to the latest version of the plugin.
Just apply my FULL SOLUTION to the page /member-access/lib/MemberAccess.php
If you are not so web savvy and have wordpress 2.7+,
* I would download and unzip a new copy of the plugin,
* find the file in question,
* open it with notepad (or your fav text editor)
* fully replace the function in question.
* save and close the file, in windows you can drag and drop the updated file back into the zip archive you downloaded. Make sure you drag and drop it back to the right directory.
* on your wordpress install, delete the member access plugin
* then using the "Add New" feature in your plugin menu find the updated plugin zip file and upload.
I hope this helps out.
Thanks,
=-)