pdf print/screen quality

Hi,

We predominantly issue many of our drawings in PDF format, and what I have noticed is issues with fonts (on screen) in adobe acrobat (pro & reader). I have attached two file formats PDF and JPEG. In both files formats we have attached text which has been created in Microstation (the bottom half of text) and the other half has been created in Adobe InDesign (the top half of the text) When viewing in adobe reader the top half is a lot clearer, which is probably expected due pen tables, etc...., but you do see issues with the fonts, especially i's, l's, etc.... as a tester we created the same piece of work in a jpeg format. The results are different in that the visual appearance with the fonts seems to have disappeared.

has anybody come across this before and possibly how to rectify the problem

thanks in advance