Your buttons appear to work fine, and we have not had any service outages at our end in quite some time, so the problem is with your own wireless connection, which you will need to sort out with Usemynet support.
The way your Buy Now buttons work, clicking a button tells the buyer's browser to contact e-junkie.com, so we can look up the product details (name, price, etc.) and transfer those details to PayPal, while we redirect the buyer's browser to PayPal's checkout site.
The "waiting for e-junkie.com to respond" message and eventual timeout simply means your wireless device is trying to contact E-junkie's server and failing to establish contact, which would happen if your wireless router is dropping your connection to that device or blocking connections to the Internet at large.
Wireless connections can sometimes be unreliable, so a device that connects fine from one area may have a flaky connection or be unable to connect at all from another area, or the connection may drop out as you move from one area to another.
If you are selling access to your own wireless router as a public wifi hotspot, perhaps the problem is that the Usemynet software thinks your wireless devices have not paid to access the Internet, so it's blocking those devices from viewing anything other than your page that asks for payment whenever anyone tries to connect -- just the same as what your hotspot buyers would see.
You may need to grant a special exception for e-junkie.com and paypal.com, so your hotspot buyers can at least connect to those servers to complete their payments before they'd be granted general access to the rest of the Internet. You may also need to grant special access to your own wireless devices, so they can connect without being required to pay. Again, you would need to work with Usemynet support to sort this out, as none of that involves our system, and the aspects of your setup that do involve our system seem to be working fine without your wireless router issues interfering with the connection.