The search entry on Open Web Tools Directory¹ is too big in Epiphany (WebKitGTK). It works fine in Firefox 3.5 but also on Chromium, so this is not a general WebKit problem.
Created attachment 32381 [details]
Here's a very reduced test case. I really wonder why Chromium and Epiphany handle this differently.
Created attachment 32382 [details]
Screenshot of testcase in Fx3.5 vs Epiphany/WebKit
This appears to be resolved now that WebKitGTK+ uses the GTK+ theme font setting for form controls. Thanks for reporting.