A while back, there was anxiety over whether Research in Motion might be forced to stop selling its Blackberry devices, over a patent infringement case. Well, for a while, everyone thought Blackberries would continue to thrive, as later on, a settlement was struck between the feuding companies that everyone hoped would make all sides happy.

Unfortunately, it now appears that RIM and NTP cannot play nice as rumors surface that the deal is starting to unravel, again raising the possibility that those cool little gadgets that companies depend on for mobile e-mail will soon go the way of the dodo in the US:

For three and a half years, patent claims by NTP, which is based in Arlington, Va., have been a cloud over Research In Motion, based in Waterloo, Ontario. But the announcement last week that a $450 million agreement reached in March was unraveling came at a particularly delicate time.

In a court filing that followed, the privately held NTP indicated that if the settlement cannot be revived, it plans to invoke an injunction banning sales of BlackBerry devices and their e-mail service throughout the United States.

According to the above-quoted article, a deal was struck where RIM believed it would be able to pay a one-time lump sum of $450 million to NTP holdings, the owner of the rather broad and vague patents in question and the plaintiff in the lawsuit, and essentially be allowed to move on. But, as is typical, it appears now that NTP has decided $450 million just isn’t enough, and they are now asking for more payments.

It’s interesting to note that NTP holdings doesn’t appear to even have a web presence, bolstering the opinion of many that the company exists solely to gain income through overbroad patent royalties and lawsuits.