>>>It looks like the font for the message area has recently changed. I find it a little harder to read, it seems a little smaller and isn't always rendering as cleanly (in FireFox, anyways). It's hard to find an example, the closest I could find is the second "t" in "Chatter" near the top of the attached image.
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>>>Alignment of some elements is off as well. When reading a message, all of the header captions except Forum and Category are vertically misaligned with respect to the field contents (as shown in the image). Maybe this is a side effect of the font change (?)
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>>I see the misalignments, but I rather like the font overall.
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>>I believe you can go to the Options page and set it back to the old Arial font in the "Message and Treeview font" section.
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>Could someone please give me a hint what options page? I have a blonde moment ...
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>The recent font is unbearable ...

Top of this message block there is an "Options" tab. There you change the font type and size.