Error chaining to file with embedded procedure call in Klist

I may be telling you something you already know but I thought I would share
a problem I recently discovered.

This code will compile.

Chain (key1:key2:key3:getKey4(var)) file;

where getKey4 will return a variable the same size and type as key4.

However when this code is run the program blows on that statement saying
that the number of key fields is not valid. One problem is the file that is
reported on the message is not the same as the file chained to. It is the
previous one.

Anyone else been "bit" by this?

Thanks
Chris Bougher