I have the same problem, qdisk votes not in cman and it was effectively a problem with the device name I was using :
<quorumd device="/dev/mpath/qdisk1" .../>
replacing with :
<quorumd device="/dev/mpath/qdsk1" .../>
has solved the problem (the first device name length was 17 chars, and the second 16 chars, hitting the #define MAX_CLUSTER_NAME_LEN 16 limitation).
Perhaps a better error reporting is needed in qdiskd to shows that we have hit this problem. Also using a generic name like "qdisk device" when qdiskd is registering its node to cman is a better approach.