Sorry if this is not the correct forum to report a possible bug. I noticed browsing the "Example of second-order singular perturbation theory" section of the "Perturbation Theory" page on wikipedia: --- Consider the following equation for the unknown variable <math>x</math>: :<math>x=1+\epsilon x^5.</math> For the initial problem with <math>\epsilon=0</math>, the solution is <math>x_0=1</math>. For small <math>\epsilon</math> the lowest order approximation may be found by inserting the [[ansatz]] :<math>x=x_0+\epsilon x_1 (+\cdots)</math> -- that the markup fonts of "x" in each of the :<math> sections are different. In particular there are no serifs on the top x's in the first equation and x_0=1 on my Linux box. On the others, there are small serifs. I don't see why they should be rendering differently. The ascii certainly doesn't indicate anything to me... I've tested this on: IE7.0 Windows Safari 4.0 on OSX 10.5 Firefox 3.5 on OSX 10.5 Firefox 3.0.10 on Linux 2.6.18-128.1.10.el5 I've attached a small screenshot of what I see. M