Memory issues ZIP vs. TAR

WP 3.2.1
backWPup 2.1.0
php 5.2.12

With some of the former updates of backWPup we had issues to get them to run properly. Daniel was extra helpful to address these issues, big time thank you to him. This plugin is outstanding, period.

Here’s an observation:

In the given configuration the plugin is stable and is working. Our backup file has the size of ~ 300MB. By choosing the creation of a ZIP we now constantly run out of system-memory (32MB, php.ini).

The creation of a TAR file is running well (except for a few files with too long of a file name).

Per se for us not a biggie, but worth noting it.

Ideas?