i have several tabs open at once, and some i have on the reload every add on, which worked fine until just lately... FF can get up to 1.2 million mem usage, then crash.. and it doesn't take too long to happen either...

I deleted all add ons and themes that i dont need/use... cleared cache/cookies... wondering what else it might be?

Have you tried using less tabs or even no tabs? Have you tried reinstalling or updating fire fox? How much memory do you have?

What is actual RAM usage by Firefox right now?

Please, post some computer info:
- processor type, amount of RAM (hold Windows logo key, hit Pause/Break key)
- hard drive size/free space (open "My Computer", right click on hard drive letter, click "Properties")
- installed security programs (antivirus, firewall)

1.66 ghz, 1.99 GB ram.

65.7 GB unused space, 45.9 GB used

I have Avast and windows firewall..

This has happened before and i updated FF which fixed the problem.. I have done all the updates, and am still having the problem. I'm hardly doing anything at the moment, 4 tabs open, and am at almost 400k.

400k seems to be excessive.
How many add-ons? Default skin, or some other?
For how long FF has been up?

It hasn't been open very long... it just keeps going up and up until it gets to about 350-400 even when I'm not doing anything. And if I have Reload Every turned on, it gets up to a million in no time at all.

I have no themes or anything extra, aside from 2 or 3 add ons.. I deleted the ones i don't use, but only had 5 total anyway.

I've done a spyware check with ad aware, and spybot... nothing major turned up.

What version of firefox? Im using 3.5 Beta 4 and just opened up A LOT of tabs (not sure how to check, but i spent 20 seconds just going over all my bookmarks opening them). My memory only went up to about 178MB.

Do you have v3?

i have version 3.0.10

400KB of 400MB? I've also had FF go as high as about 180 mb depending on what I'm doing & thats for FF 2. If java is running it runs higher than normal. Do you have video going or large pictures open? What do you have when you only have 1 tab? When FF gets that high how much memory is being used by everything?

Find the FF folder and click on the link that says safe mode. Then click on continue in safe mode. That disables all of your add ons temporarily. What does it run then?