Okay...this is an easy one. Open the file that needs fixed into DXTbmp. There are two "windows"...the one of the left is the texture and the one on the right (smaller one) is the alpha channel..which is what produces transparency in CFS2. Go along the menu bar at the top, where it says File, Prefs, Image, Alpha)....select Alpha. Scroll down to the middle section and click Create Alpha Channel (Green). This command will tell DXTbmp to search the main texture image (left window) for any true green (which is very very rarely used in paint schemes) and to create an alpha channel for that area. Since there will be no true green, DXTbmp will produce a new alpha channel that is blank...there by no transparency.
There can be a snag to this from time to time. If part of the original alpha channel works to make the canopy glass transparent and you remove the alpha channel, the canopy glass will be solid and not see through. If this happens on your B-10, let me know and I will give you step by step instructions on how to get the glass to be transparent again.
The reason the Gray ones are semi-transparent is that they are intended to depict bare metal. In FS2004, the alpha channel is used to produce shine....the gray texture with the alpha channel, in FS2004, looks like polished shiny aluminum. When those type of textures are brought into CFS2, the alpha channel causes the texture to be semi-transparent. CFS2, as I stated above, uses the alpha channel for transparency and shine is determined by settings within the MDL file....which is the exact opposite of how it is done in FS2004.
OBIO