oh come on Jerry! FF asked me if I wanted to update this afternoon and it was done in 30 seconds! problem solved, one problem fixed compared from IEs 100+
If you want to know about flaws go read the bug reports on bugzilla just search for critical ones and you can try fix them!
Thousands of people are helping to improve FF! So as the user base grows so does the bugs found... But that is why I use it! Bugs are fixed faster so your browsing is safer.
There is no perfect browser and wont be.. Only safer and better tested ones