libc (?)

[james]

G'day

I've just installed gimp, via the 5.1 distfiles, and get the following error 
message;

[smokey at gw:~]
/usr/libexec/ld-elf.so.1: Shared object "libc.so.5" not found

How would I fix this? - what do I compile etc that will remove this error message?

I did a buildworld a while ago to 4.8 stable, and ever since then I've received 
this error message (ie, amavis doesn't work anymore :-(

Any suggestions, or pointers in the right direction would be greatly 
appreciated :-)

regards
james