Version:           4.0.3 (KDE 4.0.3) (using 4.0.3 (KDE 4.0.3), Kubuntu packages)
Compiler:          gcc
OS:                Linux (i686) release 2.6.24-16-generic

I'm not sure if this is a Konqueror bug or a bug in the run window that gets triggered by pressing ALT+F2. Often when entering a URL in the run window the last letter gets cut off (e.g., instead of trying to open a URL with a .com top level domain, Konqueror will attempt to open a .co domain). Whether or not this happens seems to be related to typing speed. I can reliably replicate the behavior by typing, e.g., "www.google.co" in the run window followed by (in quick succession) "m" and ENTER. I can briefly see the complete URL ("www.google.com") in the run window before Konqueror starts. So it seems that letters entered in a small time window before hitting ENTER are not picked up by (or transmitted to) Konqueror.