Error with eruby: "Exec format error"

My eruby setup has been working fine for the last few weeks, and then
I start working again this morning and every single .rhtml file I try
gets me this error:

(8)Exec format error: exec of /home/httpd/wrecs/cgi-bin/eruby failed

It doesn’t matter what’s in the .rhtml file: I tried with a file that was just

… and I got the error then, too. I’m using eRuby 0.9.8 and ruby
1.6.7 on a LinuxPPC box. Any ideas on what I should do?