Gstreamer error when playing files from grooveshark plugin

When trying to play (any) tracks from grooveshark plugin one gets GStreamer error. This is regression introduced by revision 1599.

Steps to reproduce:
1. Launch Moovida
2. Go to Grooveshark plugin->Popular->Songs
3. Try to play any song

Expected Result:
Song plays

Current Result:
Song soesn't play and the error message is shown: "GStreamer error: Could not open resource for reading."

Bellow is the relevant traceback:

** Message: don't know how to handle text/html
WARN MainThread default Dec 07 13:56:47 Gstreamer Could not open resource for reading.:..\..\ext\soup\gstsouphttpsrc.c(991): gst_soup_http_src_parse_status (): /GstPlayBin:playbin2/GstSoupHTTPSrc:source:
404 Not Found (elisa\plugins\poblesec\player_video.py:613)