JSTOR works in general, you'd see this forum swamped with posts if it didn't (we get about 2/hour when it's actually broken). This issue is limited to you and obviously there was no way we could try to help you before you reported it.
Please run through these:
http://www.zotero.org/support/troubleshooting_translator_issues
and if they don't help, start a new thread (note that that last post here is more than 1 1/2 years old, so nothing in this thread is relevant) and provide all the information required in the last step.
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Please run through these:
http://www.zotero.org/support/troubleshooting_translator_issues
and if they don't help, start a new thread (note that that last post here is more than 1 1/2 years old, so nothing in this thread is relevant) and provide all the information required in the last step.