Thanks for the feedback. The recent Reddit changes did temporarily break the extension, but that should be fixed in the latest update (v3.2).

Regarding the "Too Many Requests" error, the extension is designed to be very light. It makes a maximum of 4 requests per minute (2 for your profile, plus up to 2 for subscriptions to "other" comments or posts). This is very unlikely to be enough to trip Reddit's limit.