Win32 CPU Cycles vs 'Live Protection' Engines ?

I wanted to document an issue I encountered when first installing and using the Bitcoin software.

Despite a correct installation and port forward settings I noticed that Bitcoin was not generating any coins or 'blocks' despite having 20+ connections for the first 24hrs. The block count just remained at 0. After realizing that Bitcoin was not 'catching up' with the collective network block download or generation I opened up the Task Manager to investigate the issue further.

I noticed that the bitcoin.exe process seemed to be 'fighting' for CPU usage against MsMpEng.exe (Microsoft Security Essentials). I hadn't noticed any system slowdown due to having a fairly high spec. PC. After adding bitcoin.exe and the appropriate program folder locations to Exclude 'Files and Locations' and 'Exclude Processes' - Bitcoin instantly started generating blocks and the CPU processes returned to normal.

I did not have any virus alerts or even 'false positive' identifications for Bitcoin. I know that the software is 100% OK. I'm assuming that the 'Live Protection' engine in Microsoft Security Essentials just doesn't 'play well' with some aspect of the CPU hungry cycles used in 'block' generation.

I have yet to do more testing, however I also encountered the same issue when using Comodo Internet Security (free version).

This is obviously going to be an issue for lots of new Bitcoin users who will perhaps be less 'tech savvy'. Has anyone else encountered any similar issues ?