Under Windows 95/98/Me, if you increase the thickness of patterned line, the line pattern buttons are disabled even though the patterned line is still displayed on the screen.

Windows 95/98/Me cannot display patterned lines for lines thicker than 1 device (screen) unit – Windows NT/2000/XP/Vista can. Under Windows 95/98/Me, Metafile Companion disables the line pattern buttons whenever the line thickness exceeds 1 picture unit. However, depending on the resolution of the screen and the current zoom percentage the line thickness may scale to 1 device unit in which case it is drawn with a pattern.

Change the line thickness to 1 (or 0) before changing line patterns.