It seems that Jerusalem is always written "ḥaser" (defective) in the Bible: that is, as ירושלם, without the י/yud, as opposed "malei" (full), as ירושלים. See, for example, Isaiah 62:6. This presents a problem when vowelizing texts, since a printer would need to figure out where to place the chiriq (the "eee" vowel). Some editions try to stuff both the chiriq and the patach or qamatz from the preceding letter under the ל/lamed. Others might try to put it under the ם/final mem (e.g. http://hebrewbooks.org/pdfpager.aspx?req=43492&st=&pgnum=41).
What is the reason for Jerusalem always being written ḥaser? Is there a standard Unicode-friendly way for typing it ḥaser with vowels? (See the problem here: http://mechon-mamre.org/c/ct/c1062.htm) Are there any other such words where there is no room for putting all the vowels (not otherwise in a qeri/ksiv)? Is it even technically correct to call it "ḥaser"?
By the way, the only "malei" form of Jerusalem I could find is in 1 Chronicles 3:5. Are there any others?