Can't change the menu icon next to applications tab in certain themes

[left 4 shred]

I have become very restless and irritated while trying to change the icon next to the applications tab on my top panel (I'm using Ubuntu 10.04 LTS Desktop).

I've tried multiple methods and have had no luck.

I've used the Ubuntu Tweak option for changing the icon. It didn't work.

I've attempted taking my custom one and changing it in the directory itself but I can't figure out how to change the permissions to allow me to do this.

I've used the terminal to replace the icons but once again i was not given permission.

I've spent hours trying and trying to get this to work and I'm stumped.

Now to note the problem of this only being for a certain theme.
I changed the theme from my custom theme (the one I want to change that icon for) to the Ambiance theme. I opened up Ubuntu Tweak and tried using the simple icon changer button...it worked. I had just d/led updates for it so I switched back to my custom theme to try it and nothing.

I don't know whats wrong. If anyone has any suggestions or know any solutions, please let me know. This isn't a vital problem or anything, it's just been very irritating.

Extra:

The custom theme i'm using is this

Controls: snow-leopard-mac (i don't remember where i d/led this)

Colors: N/A

Window Border: Mac4Lin_GTK_Aqua_v1.0

Icons: Mac4Lin_Icons_v1.0

Pointer: Default

[left 4 shred]

I've figured out the permissions problem. I typed

gksu nautilus

into the terminal and I was able to drag my custom icon where ever I wanted it.

I am still facing a problem though, I can't find where this particular gnome foot icon is. I've done some searches but I can't seem to come across it.

[left 4 shred]

-bump-

[Timmer1240]

Im on karmic but I did the same thing by replacing the system logo Icon in the downloaded Icons then I installed the icon theme in the appearence preferences but may not work with lucid

[Timmer1240]

I got a mac 4lin v.04 icon theme untared the distibutor logo is in scalable folder then in places folder if you replace the icon in there with your custom logo and THEN compress it then rename it to custom or something install the customized icon theme into apperence preferences then yout logo should be at the top hope this helps thats how I did mine!see!

[left 4 shred]

Alright sweet. I'm gonna give this a try. I'll let you know if it worked for me or not, either way thanks for the input!