Same problem for me with hostgator. It used to be Chrome only, now IE doesn’t work with Press this using hostgator 4.2 & newer press this bookmark. Here was Hostgator’s response:
Unfortunately, issues with compatibility of plugins/scripts between different browsers would not be something which we can assist with. The best course of action would be to speak with the developer to determine if this is an issue which they have seen before. Most likely this has to do with differences in the way which the browsers interact with the script. If they provide you with some suggestions which include recommended changes to the hosting environment, you may forward these to us and we will evaluate the changes for you and make any which can be implemented. However, the fact that it works with any browser indicates that the issue is with the software and not with the hosting services.
Let us know if you need any additional information. We’ll be happy to provide any you might need.
Cheers,
Robert D.
Linux Support
1.866.964.2867 / +001.713.574.5287
https://support.hostgator.com