This is off topic... but on topic - is there something known as to Comodo and flash?

Eureka! Having focused on the Firefox-flash behavior, I completely forgot I had the "IE Tab" add-on installed...so I went to megaupload, changed the render engine (which I assume is what "IE Tab" is doing - could not find "iexplorer.exe" process running and it was allowed to access the internet despite having allowed Firefox only) and presto, no more slowdowns, the web page loads quickly and is a smooth experience! Firefox isnt perfect but "IE Tab" makes a real difference (at the expense of using more ram). This might not be the idle fix but it works

EDIT: Need to kick myself in the nuts now for ignoring such a simple way around this "problem"

Does this say that you had incorporated the extra exclusive settings into your ini? And that the thing was set to the IE Tab - that was the conflict?
mitch

Thats how I "allowed (internet access to) Firefox only" in the ini file. The "conflict" is still unknown to me (might be the way Firefox reads a flash site, or maybe its the lack or "write" ability to the location of the flashplugin, cant say for sure tho). IE Tab is the fix - It's an addon that forces Firefox to use the Internet Explorer render engine rather than its own render engine (without invoking iexplorer.exe), so bascically to solve the problem I launched Internet Explorer inside Firefox (sounds confusing eh) Its more of a work around than a fix to be honest...

With the normal engine (the one called Gecko, not IETab), does unsandboxed Firefox work well with Flash?
In other words, should I be looking into the problem of viewing Flash-heavy sites with a sandboxed Firefox?

Well, your settings prohibit IE from reaching the web, and that was what you were trying to do. Im not sure how the conflict issue isn't solved here as I think you're good to go.

Just that it is important to us to identify these "out-of-the-way" conflicts so Tzuk has increased info for his GUI. thanx
mitch
edit- ok I'm back on speed (so there remains a conflict between Firefox and flash while sandboxed, this is a fix for your particulars)

Thats correct, unsandboxed firefox loads and flash site without a hitch but when switching to sandboxed Firefox, there's between a 30% to 50% more overhead CPU usage (cant say this is true for ALL users tho...).

Tzuk, this thing is all over google - both IE and Firefox - I couldn't reproduce, but I couldn't access the videos on megaupload either. Redtube is similiar in nature and none of us have problems there. So no, I do not think this is a Sandboxie related issue.
mitch

Yeah, i've tried Megaupload and Youtube in a sandboxed instance of Op, IE and Fx and they use just as little memory as they do unsandboxed. It's most likely some kind of conflict with something on their pc's and not with Sandboxie itself, or else we'd all be having this high memory problem.

Its not a memory problem, its excessive CPU usage. It increases a lot when surfing flash sites while sandboxed.

Tzuk, I was referring to CPU usage and memory in my answer.
mitch

ha, your right stef, well I meant CPU usage, im just used to typing memory, ha.

My opinion on this is that when a user incorporates the extra settings in their ini file he creates a special situation that involves Flash and Media Player.

Internet Explorer invokes those helper programs as "child processes" and allows them to run. Even though the settings would otherwise prevent it.

On the other hand, (and I need some Firefox help here), Firefox via the plug=in route is not invoking those programs in the same way. Firefox may even launch them as their own process or semi and so...... problems.
mitch
ps - I also add that those settings have never been presented as anything other than a "tweak" and a user with problems owes us the explanation that this has in fact been done. When I tryed to reproduce the problem via Firefox- I did not have those settings in the ini.

Now that I've found a work around for my particular problem, I'm also trying to figure out what could possibly cause the slowdown but first we need to identify the so called problem:

On specific web sites (only those containing flash, i've tested with megaupload and youtube) a sandboxed instance of Firefox leads to high CPU usage. Switch to non sandboxed instance of Firefox - no apparent abnormalities in CPU usage. Repeat process with Internet Explorer, again no CPU hog. Disabled firewall (Tiny Personal Firewall) and antivirus (Avira AntiVir Personal Edition Classic) and tried again - Firefox+flash conflicts resurface while sandboxed. User (myself) is left baffled. User tries to trace for errors but has no luck as the trace reveals nothing errornous.

User tries all sorts of solutions - from copying the entire flash plugin directory inside the sandbox (and pointing an OpenFilePath towards that directory) to adding an OpenFilePath pointing at the original flash plugin directory.

User then recalls having installed a certain Firefox addon called "IE Tab" and decides to use it with the outcome being bypassing the conflict (but not eliminating it).

Ok, well we were involved a bit also. Would you mind one final test by removing the extra settings from your ini file? Or actually quicker would be I'll just add them to mine.
mitch