It seems that PHP is limited on memory and it's running out. We'll adjust the memory detection in the plugin in a future version to better anticipate this.
Please uninstall the tracing version and install the normal version again. You'll need to reconfigure it I'm afraid.
Then please go to General Settings. The address bar of your browser will say:
You just need to change this URL to the same thing but ending in "advanced" instead of "settings" as such:
On this special page, leave everything else as it is, but look for "max_block_size".
This is the amount of memory the plugin will use during backup, and is automatically calculated (thus we can improve the calculation in future version)
What you need to do is just tick the box next to it (which then tells the plugin, don't calculate it, use what we say instead), and then edit the value so instead of 8388608, it says something like 5000000 (that's 6 zeros.) Then click Save Advanced Settings.
If you still get timeouts, drop it more, but don't go any lower than 1000000. Let us know if it has problems even this low.