Twitter and Facebook aren’t about to make nice yet.

The microblogging network released an update that was supposed to let users import their Facebook friends and LinkedIn connections, but its much bigger rival appears to have shut down the feature.

“Facebook has notified us that they have blocked the update to our application, and we are working on a resolution with them,” said Carolyn Penner, a Twitter spokesperson.

Usually, when a larger company like Google, Microsoft or Twitter wants to build an application on its platform, Facebook has more in-depth talks to ensure the site can handle the technical load.

Facebook said that it’s working with Twitter to resolve the issue, according to spokesperson Malorie Lucich. We’ll see if Twitter gets the green light in the long run.

The Twitter update was supposed to let users check which of their Facebook friends were on its site already and then choose whether to follow them. It potentially could have introduced millions of Facebook users to Twitter and signaled a more peaceful era of co-existence between the two companies.

Earlier this week, it looked like the rivalry, which reached its zenith last year when Facebook copied several Twitter features, was about to cool down. Mark Zuckerberg said in an interview earlier this week that he paid too much attention to Twitter last year. He added that the competing network’s growth was “unnatural” and he had been mistakenly concerned that it put Twitter in a position to surpass Facebook.

However, Twitter’s growth has been accelerating in raw terms, with about 340,000 new users joining a day up from 300,000 in April. In contrast, Facebook’s growth might actually be slowing. While it accumulated about 50 million users roughly every two months into February, it has yet to announce that it crossed the 500 million user mark — a milestone that would’ve happened sometime in the last few weeks if the growth had continued on that trajectory. Facebook will reportedly pass this mark in mid-July instead.

Perhaps Facebook employees know all too well that only the paranoid survive.