Hello MasterX!
This is something strange I experience every night! When I still had daylight saving time here in Germany, this time of the day always had been after midnight! For about 15-30 minutes all API calls fail and BTC-Trader doesn't work properly. You can use the MtGox web interface during this time.
I don't know why this is so, but every night it is like this! You can't use BTC-Trader during this time!
However, after 20-30 minutes everything works fine again. I guess, that every night there might be a kind of MtGox API maintenance. I submitted a support request to MtGox support this night. Let's wait for their answer. I am curious about this, too!
But I know this problem well, since I experience it every night, too.
Just try again about every 10 minutes and you will know how long it lasts this time.
Best regards
Andreas