I would like to say that I am a huge fan of Portable Apps 'SeaMonkey' & use it a lot at work. I have noticed that SM 2.6.1 portable hasn't been upgraded to SM 2.7 yet. This is quite fortuitous in my opinion as SeaMonkey 2.7 seems to be suffering from the same 'flash/Java cursor bug' that Firefox 10 is suffering from. I have returned to SM 2.6.1 on my C-Drive & 'wound-back' my Firefox portables to 9.0.1.
The bug appears to make the cursor disappear on certain sites like YouTube & also affects highlighting in the runbar (essentially making it impossible to highlight a Web address).
Here is a link to mozillaZine about the problem: