Hi Phil,
It may be that Outlook is associated with iCalendar subscriptions and that Thunderbird is causing it to open for some reason.

If you have any further problems, would it be possible for you to contact us so we could discuss some details?

Thanks!

@ Phil, I had the same problem...it was the RTM provider extension. It doesn't work with TB 5, so I removed it and no longer get the additional pop-up when TB starts.

HTH
- John

Hi John,
Thanks for providing that information; we'll keep that in mind for any future issues as well.

I am also having the same problem.

davidbone,
Would you be able to contact us so we can take a closer look? Please let us know if you're using the provider for Lightning that jtruchon mentioned.

Thanks!

I'm having this same problem, trying to integrate RTM with Thunderbird 5. There used to be a provider, but it is now no longer working.

The Thunderbird/Lightning provider for Remember the Milk was created by a third party developer. Unfortunately I'm not familiar enough with this add-on to be able to say why it's causing errors with Thunderbird 5, but the developer may be able to help you.

I'm sorry we're not able to provide support for third party apps.

Hope this helps!