I introduced an error into the batch Z39.50 search function. This was corrected in this build. The change affects the z39.50 client (as well as the redistributables). Here are the download links:
MarcEdit App: http://oregonstate.edu/~reeset/marcedit/software/development/MarcEdit51_Setup.exe
Runtimes: http://oregonstate.edu/~reeset/marcedit/software/development/MarcEdit51_Runtimes.exe
–TR