newbie: question about string output, when is type printed

[abs_zero]

How come when you leave out comma concatenation, it prints out the type , but when you include the comma it doesn't?

Example:
<<< now / second, "seconds" >>>;

yields:
10906.540408 seconds

but removing the comma and just printing the expression:
<<< now / second >>>;

yields the following:
10964.996644 :(float)

it basically appends :(float) to the value output, but doesn't do it when there's a concatenation present.

note: i'm using miniaudicle for windows 7, but it's the same output in command line.

[Antimon]