Darn! The termcap database in OS X is wrong. You should fix it.

1. Edit the file /usr/share/misc/termcap, changing the entry for vt100 to this (note that there's no space in front of the first line... that's to deal with wiki):

 d0|vt100|vt100-am|vt100am|dec vt100:\
    :Co#8:Sf=\E[3%dm:Sb=\E[4%dm:\
    :do=^J:co#80:li#24:cl=\E[;H\E[2J:sf=2*\ED:\
    :le=^H:bs:am:cm=5\E[%i%d;%dH:nd=2\E[C:up=2\E[A:\
    :ce=3\E[K:cd=50\E[J:so=2\E[7m:se=2\E[m:us=2\E[4m:ue=2\E[m:\
    :md=2\E[1m:mr=2\E[7m:mb=2\E[5m:me=2\E[m:\
    :rf=/usr/share/tabset/vt100:\
    :rs=\E>\E[?3l\E[?4l\E[?5l\E[?7h\E[?8h\E[;r\E[0m\E(B\E)B\E[2J:\
    :ks=\E[?1h\E=:ke=\E[?1l\E>:\
    :ku=\EOA:kd=\EOB:kr=\EOC:kl=\EOD:kb=^H:\
    :ho=\E[H:k1=\EOP:k2=\EOQ:k3=\EOR:k4=\EOS:pt:sr=2*\EM:vt#3:xn:\
    :sc=\E7:rc=\E8:cs=\E[%i%d;%dr:

2. You should note that it's only the second line that needs to be inserted into the existing entry.

3. You reconstruct the database with:
cap_mkdb /usr/share/misc/termcap

4. Quit and restart Terminal, and you'll pick up the new termcap entry.

All this is done as root.

These instructions were gleaned from http://www.google.com/search?q=cache:eP_G8AlM17EC:www.ahdore.com/craig/v...