The fonts of old papers (<2000) tend to look disheveled on my Linux box. Why is that?
There's the paper: http://acl.ldc.upenn.edu/H/H94/H94-1048.pdf
This is almost certainly due to the scanning process (whether OCR was used or not). Journals started using electronic publishing relatively late. Most older papers have been scanned into PDFs from the original, printed paper version. That's why the fonts look weird to you.
What you are looking at are images taken of the fonts and then (maybe) passed through OCR software to turn them into text. Newer papers look better because they have been created as PDFs directly.