small cyrillic bold м looks ugly in Firefox

[LoonyPhoenix]

When browsing Russian sites, when you come across a bold small "м", most often it looks really ugly, like a rectangle. Observe, for example, Gmail Settings in Russian.

[LoonyPhoenix (loonyphoenix)]

Steps to reproduce:

1) Open up your Gmail account;
2) Go to settings;
3) Choose "Language: Russian (Русский)"

[LoonyPhoenix (loonyphoenix)]

PS: Apparently, it's bad rendering of Arial from msttcorefonts. When I deleted that, м's became normal.

[LoonyPhoenix (loonyphoenix)]

Same in Intrepid.

[Jean-Baptiste Lallement (jibel)]

Thanks for your report.

It looks much better now according to screenshot. I'm closing this report. Don't hesitate to reopen if it's still an issue.