problems downloading attachments w/ IMP 2.3.7

[Liam Hoekenga]

we're having problems downloading attachements w/ our installation of Horde 
1.3.5 / IMP 2.3.7... just ran cvs update, and it's still doing this.

You can "view attachments" just fine.

If you try to download, the server returns a 404:

https://mail-test.www.umich.edu/horde/imp/view.php/kitty.jpg?mailbox=INBOX&
index=12208&array_index=1&id=2&actionID=112&mime=
d2e1e29dcc66fff31748b036f13af074 

now.... if i copy and paste some stuff, and enter the following URL into my 
browser, i get a "download attachement" dialogbox:

https://mail-test.www.umich.edu/horde/imp/view.php?mailbox=INBOX&index=12208&
array_index=1&id=2&actionID=112&mime=d2e1e29dcc66fff31748b036f13af074 

which corresponds to the "view attachement" URL of...  

https://mail-test.www.umich.edu/horde/imp/view.php?mailbox=INBOX&index=12208&
array_index=1&id=2&actionID=113&mime=d2e1e29dcc66fff31748b036f13af074

any idea why my installation is trying to get "/horde/imp/view.php/filename..." 
instead of "/horde/imp/view.php?mailbox=..." when downloading (but not 
viewing)?

thanks
Liam