Hi Sandra,
I switched my server over to PHP 5.2.17 this afternoon so I could test how the HotPot module runs in that environment.
I found a couple of other places where PHP 5.2 produces a syntax error when it comes across "::". I have fixed those errors too now, and uploaded the revised scripts to the moodle.org -> Plugins repository.
Please download and install the latest version (2010080350) when you have a chance.
best regards
Gordon