[Plugin: WordPress Backup to Dropbox] Fatal error: Because of another wordpress instances in subfold

Hi,

I am trying to setup this plugin on my website but I have a problem. It gives fatal error.

Fatal error: Allowed memory size of 157286400 bytes exhausted (tried to allocate 4224 bytes) in /home/xyz.com/wp-content/plugins/wordpress-backup-to-dropbox/Classes/class-file-list.php on line 114

I tried to investigate this issue and I noticed that this error goes away if I remove/move another WordPress that I have in subfolder. Although I don’t want to backup that subfolder and want to exclude it. But not sure why this happening because I installed this plugin successfully on another website that have 2 more WordPress instances in subfolder.

Any ideas, how to fix this issue or some how skip that folder (manually).

http://wordpress.org/extend/plugins/wordpress-backup-to-dropbox/