My maps work great but if a user is editing their User Map in their account settings (and Location is set to 'collapsible' and 'collapsed' the map does not render fully [UNLESS they change the size of the browser].
Separately, in a quicktab view... I created a view using GMAP formatter in view... outputted it into a quicktab and voila, you can see the results. I used the standard |GMAP| formatter. The map does not only look normal if the user knows to resize their actual web browser page (minimizing it or maximizing it).