On my laptop, with images over a certain size (an equirectangular image at 2000x1000 works fine, but one at 2500x1250 has problems), the display gets messed up as some parts of the image appear over the top of other parts. It seems to be overwriting some of it's own textures while rendering the image (though that's just a guess). My card only has 64MB of memory, so it may just be that there isn't enough texture memory to hold the whole thing. The end result, however, is that most panaramas are unviewable on my laptop.
I have found two workarounds to this problem:
1. Reduce the size of the panorama. This involves figuring out what url the website is embeding, downloading the QTVR file it, extracting the cube sides using qtvr2img, resizing all six sides, and finally viewing the resulting smaller cube in FreePV.
2. Disable direct rendering. This requires me to log out, change the configuration of Xorg, and then restart it. This results in slow (but working) operation of FreePV, but I have to reconfigure and restart Xorg again before I can do anything that required direct rendering.
An minimal fix would be to detect when there is not enough graphics memory available and fall back to software rendering (Panini does this, but it's software rendering is much slower than FreePV's)
What would be really nice would be if FreeVP only loaded the amount of detail that is needed to display the current view, the way google earth does (which works fine on my laptop, even full screen). In other words, if the user was zoomed out, FreePV would send the graphics card less detailed textures. Then, if the user zoomed in higher resolution imagry would be used, but only for the region that was visible. Even on more capable cards, this would be useful to allow really high resolution panoramas to be viewed.