Server problem related to Custom Field Images plugin

Hello.

I’m trying to get scribu.net’s Custom Field Images plugin working on a site. I tried to install the plugin and got this message:

Parse error: syntax error, unexpected T_CLASS in /blah/blah/blah/blah/blah.com/wp-content/plugins/custom-field-images/custom-field-images.php on line 72

I’m not much of a PHP person, and I did a couple of searches but I couldn’t find much more info about this error.

So, on a hunch, I decided to try and install the same plugin on a totally different site, on a different server, just as a test. It installed fine — no errors.

How do I get it to work on the first site?

Thanks.

Edited to add…

Site #1 is running WP 2.8.2, totally up-to-date. Site #2, where the plugin worked, is running 2.8

Edited, again…
I just tried to get the Breadcrumb NavXT plugin working, and got a similar problem. This plugin is actually two plugins: NavXT Core and NavXT Administration Interface. The core activated fine, but the admin interface gave me this:

Parse error: syntax error, unexpected T_STRING, expecting T_OLD_FUNCTION or T_FUNCTION or T_VAR or ‘}’ in /blah/blah/blah/blah/blah.com/wp-content/plugins/breadcrumb-navxt/breadcrumb_navxt_admin.php on line 49

Any ideas?

Thanks…