Text justification issue

In my company, we are using a specific font, Rotis SemiSans (OpenType font). We are having issues with text justification, namely Center (Center Top, Center Center, Center Bottom) and Right (Right Top, Right Center, Right Bottom).

The markers on the left use Rotis SemiSans type, with text justification Center Center, snapped onto the thin black line. 
The markers on the right use Arial type, same setting as for markers on the left.

Again, text on the left is with Rotis SemiSans type, justification Right Center, snapped onto the thin black line. 
Text on the right is with Arial type, same setting as for text on the left.

I had a discussion this morning with the guys I bought my fonts from (a company in Prague, Czech Republic). They think it could be an issue how MicroStation handles OpenType fonts. I remember vaguely that I had this discussion about Text Justification with Rotis SemiSans font with somebody from Bentley (possibly on these forums), but I couldn´t find any traces of that.

Any ideas whether the bug is with MicroStation, or the font (Rotis SemiSans OTF)? I can email this font for further investigation.

MicroStation 08.11.09.459, Windows 7 Professional 64-bit Service Pack 1,

TIA,
Jan