Strange, because QtWebkit-plugin-Linux-4.6_2-1.26.0.14 got the QT Webkit version used with viewer 2.8...
Are you sure you installed them right, overwriting the bin/llplugin/libmedia_plugin_webkit.so file in the Cool VL Viewer installation directory ?
The original libmedia_plugin_webkit.so is 40547353 bytes large, with md5sum 1d1b7db038230656e17b401e65376502.
libmedia_plugin_webkit.so v4.6_2-1.26.0.14 is 39049533 bytes large, with md5sum d38f3c7d8836ff1a9049ed0f0ab1b4e1.
libmedia_plugin_webkit.so v4.7.1_2-1.26.0.14 is 40700300 bytes large with md5sum cd3cc69da4d53f37b5d8031f13e4d297.
As for Snowglobe-i686-1.4.2.3626, the Showcase is not working properly (click the Teleport buttons for destinations with a sim name containing a space, and see by yourself...). In any case, Snowglobe Qt Webkit is unusable with the new search engine, so I cannot go back...