I've tried to replicate this problem withlout results.
I verified source code and the '=' is statically added:
this->addArgument( QString("disk:").append( shpth_data[0] ).append("=").append(shpth_data[1]) );.
Rdesktop's (v1.5.0) man pages tells there should be the space between options and their values. Probably is a particular space, in some option value, giving problem.
There a space in the password? Or username? or in another option?.
The problem is due to rdesktop program. In fact krd doesn't crash. It reports an error given by the rdesktop instance running. Try to upgrade to new version of rdesktop.
