Some random advices:
Check your network connection settings... If you're using a proxy server try to disable it... If you're not using one try to find one (google "proxy servers" should get you some)...
If you're using Windows, click "Start -> All Programs -> Accessories -> Command Prompt", and in the Command Prompt window type in "ping www
.djape.net", and see how the connection goes... For comparison, try "ping www
.sudoku.com" and see the difference...
If you're accessing all other websites fine but only have difficulties with the djape website, perhaps someone with the same ISP as you has been blacklisted by djape, thus the connection difficulties (but it's purely my speculation)...