It can be both, as Windows 64-bit disallow Antivirus to hook the kernel anymore, so while Bitdefender trying to improve the security via other ways, it can just broke the other software, and so did the other antivirus.
So far some antivirus using virtualization to running the system inside the virtualization, but this is not very good, there are many driver will be broken if you are running with virtualization.
For example, AMD can't support DXVA to hardware acceleration decode.
This has a better explanation than me, you can just read about it.
+ Does Zemana AntiLogger 64-bit provide the same level of protection as the 32-bit edition?
Almost. At present all AntiLogger modules are fully functional under 64-bit systems, except for the screen capture module, which provides only basic protection. Our engineering team is currently working to develop the screen capture module to be 64-bit compatible and, when ready, the module will be released with our regular product updates.
What does this mean? You still get protection against the most dangerous threats, such as key loggers and SSL banker Trojans; but until the module is ready, we would advise our customers who use 64-bit computers NOT to enter passwords and other sensitive information through on-screen virtual keyboards unless they are positive that the application providing the on-screen keyboard protects it really well.
+ How is Windows 8 different and what does it mean for me?http://www.zemana.com/support/antilogger/
Starting with Windows 8 64-bit, Microsoft effectively closed any third party software from funning at Kernel level, in the systemʼs core. This is where our sensors are based. In other words, this part of your computer is now guarded by your Windows 8.
Does this mean you are immune to information stealing malware? Not exactly. To ensure protection on Windows 8 64-bit computers, we have added keystroke encryption functionality, advanced protection against SSL intruding financial malware and signature-based detection of information stealing malware. This gives you a hybrid protection, combining a number of defense mechanisms and ensures your system is safe.
Anyways, if you remember when Process Lasso start having issues, just check the update log of you AV, if the time match, then it should be the AV is a bit over on security and break some software.http://en.wikipedia.org/wiki/Kernel_Patch_Protectionhttp://en.wikipedia.org/wiki/X86_virtualization