As Birdy suggests, that model of Linksys or range of models do not work at all well in UPnP mode. They have firmware issues which Linksys never completely fixed.

There are alternatives to the firmware but using these have their own risks.

1. www.dd-wrt.com | Unleash Your Router open source version firmware. Support -> Support Database & type in your model to get available versions of dd-wrt 3rd party firmware that you could use according to your specific model.

2. http://www.gnutellaforums.com/connec...tml#post196843 this technique is not recommended to those without some technical way of thinking. This method is somewhat risky if you get it wrong.

* Fixing the firmware will fix up the Linksys reliability however, only choose this avenue if Birdy's suggestions do not work. Changing firmware will cancel out any warranty/linksys support that is left on your router.