Helvetica display problem

[Peranakan]

I have this strange font display problem with the Helvetica on my computer:

On all places where the text should be displayed as a Helvetica bold, I see the text in (what appears to be) Cyrillic Helvetica bold, making it impossible for me to read. This happens on all places where the font is used: in Mail, on websites, Texteditor, etc.

When I check the font with my fontmanager everything seems to be fine.
I tried re-installing the font with Fontbook and Pacifist, no luck.

Has anyone any other ideas to get this thing back in order?

My system runs on OSX 10.4.11 and I manage my fonts with Linotype Fontexplorer 1.2.3.

Thanx in advance.

[Giaguara]

First, validate all the fonts you've added to your system.

Then, if you can't find the faulty ones, disable all your added fonts. Does it occur? If not (which I suspect), enable 50 % of them. See if it happens. Add/remote another 50 % of the remaining ones, test.. repeat, until you find the problematic font(s). And delete those.

[Peranakan]

thing is, the Helvetica font itself seems to be working fine. But my system (or fontexplorer) for some reason prefers to display the Cyrillic version, rather than the regular or bold.
I've attached a screenshot from Mail. Al the Cyrillic text here is supposed to be plain Helvetica. Pretty annoying, as you can see. :-(

[Natobasso]

Use Tools/Clean System Fonts folder to make sure you don't have any conflicting Helvetica user fonts in the System fonts folder.

Then, make sure all your user fonts are in the hard drive only, and not in any system or library directories.

[Peranakan]

I've cleaned the system fonts folder cache with both FontExplorer as well as FontNuke. And my user font folder is empty, but still no luck :-(