It must be much quicker to click on the "Basic Commands" tab at the top of the forum page (or use Manual 2) than to start a new thread and wait for a reply!
There you will see that the timeout and address need to be enclosed in square braces [ ] .
In a lot of systems square brackets in command options do mean optional items (not requiring the actual typing of square brackets) so when the appear in the listing of a PICAXE command, I can undestand why its not clear as to whether they should actually be typed or not.
In the listing of the Serin command there are 3 bracket types;
Yes that was my understanding that the brackets meant optional, now i will know that they are required
The examples given in the serin explanations in manual2 should show an example of optional case.