There are several issues in SQLyog (and any GUI client I believe) with binary data. This is already recorded:
http://code.google.com/p/sqlyog/issues/detail?id=15
It is basically a matter of priority! We have 400 open issues and have what resources we have and we try to put efforts where demand is most (and of course requests by paying ENTERPRISE customers get priority)
added: we have 1.5 mio users that never paid a cent for the program. We have only ONE code contribution in the 3-4 year history of (Open Source) COMMUNITY edition. There must be someone out there who can contribute a HEX-editor component similar to the image display component that is currently available in the BLOB-viewer. If someone contributes we will of course include it in COMMUNITY version (with the necessary detail that license must be flexible enough also to include in ENTERPRISE).