http://openclipart.org/people/molumen/molumen_lollipops_dispenser.svg created in Inkscape 0.46 preview1 (on Windows) and saved as plain SVG appears to be not valid.
I tested it with http://validator.w3.org/
Here's what I got:
Line 16, Column 6: there is no attribute "id". id="perspective443" /><inkscape:perspective
Line 16, Column 24: element "inkscape:perspective" undefined. id="perspective443" /><inkscape:perspective
Line 17, Column 25: element "inkscape:perspective" undefined. id="perspective4412" /><inkscape:perspective
Line 18, Column 25: element "inkscape:perspective" undefined. id="perspective8338" />
Line 156, Column 18: there is no attribute "inkscape:label". inkscape:label="filter16913"
Line 164, Column 22: there is no attribute "inkscape:collect". inkscape:collect="always" /></filter><linearGradient
Molumen