In a recent blog post, Mozilla said that it has barred a Skype extension for Firefox because the extension allegedly not only slowed page-load times dramatically, but also happened to be the cause of 40,000 browser crashes a week.

Elaborating that the Mozilla bug tracker has identified the Skype extension as one of the main causes of crashes for the current stable version of Firefox, Mozilla programmer Boris Zbarsky said that the plug-in noticeably slowed Firefox’s processing of Web page elements via what is known as the Document Object Model (DOM).

Noting that the slow page-load times as well as the browser crashes “constitute a major, user-facing issue, and meet our (Mozilla’s) established criteria for blocklisting an add-on,” Mozilla elaborated that the add-on is installed by default when Skype's main software is installed.

According to Mozilla, the Skype Toolbar has been “knowingly or unknowingly” installed by a large number of Firefox users who have installed Skype.

Meanwhile, revealing that the company is working out ways to address the issue, Skype said in a statement: “Based on our initial investigation, we know that downloading the new client will fix for most users any compatibility issues, and are working with Mozilla to ensure that there are no other compatibility issues.” The company also rendered an apology for the inconvenience the add-on had caused to the users.