Looks fine to me, what about you? It works. The problem is it keeps inserting 255 as the timestamp. I even tried to substitute php's time() function with mysql's own native unix_timestamp(), and it still inserted 255.
I can't find any sites that document this happening, so no luck in fixing it so far.
The table column it's going into is an unsigned tinyint(11) which is the same as I've always used for my timestamps.