Timeout limit on readurl function?

[40k]

Anyone know if there is a timeout value in seconds for the readurl function? I'm getting seemingly random "download failed" errors in my scripts that use readurl(). Often when I try a second or third time the script works as intended. I'm on a dodgy ADSL connection in Southern Europe right now so I can't figure out if it's my code throwing a fit on just the internet here being crap.

[admin]

No timeout built in by me. Must be something else.

[40k]

No timeout built in by me. Must be something else.

What could cause the readurl() function to throw "download failed" one time but it will work on the next attempt? No response from the server perhaps?

[admin]

Anything that causes an imperfect transfer of bytes could be the reason.