I believe I may have found a bug. I can reproduce it reliably on my machine (Windows 7 x64, 16GB RAM, IE 10, nVidia GTX 560). I have tried disabling GPU rendering and the bug still occurs.
The easiest way to explain how to reproduce the bug is as follows:
1. Close all instances of IE and verify none are left running using Process Explorer.
2. Start one new instance of IE. This will be kept running and won't be closed.
3. Start a second process e.g. by creating a new InPrivate session by right clicking the IE icon and selecting "New InPrivate Session"
4. Open 30 new tabs in the InPrivate session, using the Ctrl+T shortcut 30 times.
5. Close the InPrivate session.
6. Repeat steps 3-5. Monitor the child processes being spawned by IE using Process Explorer.
7. Repeat steps 3-5 once again. You should notice that IE stops spawning new processes at some point.
8. Now, as long as the original instance of IE is running, IE will not spawn any more than one child process per instance of IE. This will lead to the memory of that child process growing and eventually IE will stop rendering new tabs. Flash may also stop working. E.g. if you repeat steps 3-5 again, you should see only one IE process being spawned.
Please let me know if you can reproduce this.
Chris Shields