Ok, first the small bugs:

When no sound card is configured dia starts with the message "/dev/dsp: No
such device". When configured and running under KDE the message says
"/dev/dsp: Device or resource busy". Okay, old story ... however, this
message is really unnecessary ... 

Now the not so small ones:

trying to drag the menu bar somewhere else crashes dia

opening an new diagram, choosing an activity/data flow (SADT - first
symbol) and trying to draw something hangs X. The mouse cursor is frozen,
keyboard doesn't work (Ctrl-Alt-Backspace doesn't work). I can still telnet
to the machine. telinit 3 does nothing (well, it does, but the screen
stays the same). telinit 5 afterwards - the same result. telinit 3, killing
a X process and an autorun process - as above. reboot - the screen stays
the
same until the machine restarts.
same for UML - create a state machine
same for Network - Storage
same for Sybase - stable storage device