Comment 25 for bug 704623

(In reply to Wil Clouser [:clouserw] from comment #18)
> It's still taking ~25s before I have a window open when starting thunderbird
> but I'm no longer seeing the unresponsive script warning. Perhaps deleting
> the newsgroups got it under that threshold.

Gain by deletion of newsgroups seems 5 sec only.
Do you have big message filter? Because msgFilterRules.dat is read one byte each(Bug 571419), big msgFilterRules.dat may affect on startup time when "new mail check upon startup" is enabled. What is file size of msgFilterRules.dat files?

Slowness is observed upon any restart of Tb? Or first restart of Tb after login or re-boot?
On Win, because Fx/Tb/Sm modules are not loaded(and cached) by re-boot, first restart after re-boot is far slower than IE, but second or later restart is not so slow because already cached. Virus scanner may affect on it too, because virus scan may be invoked on first load but it may not be upon second load.
Is this kind of slowness involved in your case?

By the way, can you use monitor tools? If you can use monitor tool for application's file access, it may help your problem analysis, because activities of Tb during restart is reflected to file access by Tb.
Bug 571419 was fortunately discovered while I was viewing Process Monitor log on Win for duplication test of other different problem. Flood of log lines for specific file/directory, too many repeated access to specific file/directory etc., is sometimes signal of something wrong around process related to the file/directory, and, by flood of log lines for msgFilterRules.dat, I was aware of the problem.