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locks up when downloading, cannot perform other actions

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Maybe not a complete lock up, but response to input from the keyboard or trackpad takes maybe 30 seconds. this happens on every download from every site.

Downloads seem to take a long time as well. DSLReports.com speed tester says my DSL line is average for download speed for my plan.

This problem has been occurring for a couple months at least.

Maybe not a complete lock up, but response to input from the keyboard or trackpad takes maybe 30 seconds. this happens on every download from every site. Downloads seem to take a long time as well. DSLReports.com speed tester says my DSL line is average for download speed for my plan. This problem has been occurring for a couple months at least.

All Replies (7)

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Oh, is there anything in About:Config that I might have screwed up to cause this? Like setting it to have a small maximum number of ports open at once?

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Start Firefox in Safe Mode {web Link} by holding down the <Shift>
(Mac Options)
key, and then starting Firefox. Is the problem still there?


Start your Computer in safe mode with networking. Then start Firefox. Try Safe web sites. Is the problem still there?

Starting The Computer In Safe Mode;
Free Online Encyclopedia

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Seems to work fast when there is only one window open, either safe or normal mode. The problem is under normal operating conditions, with many tabs & windows open.

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Is the problem there in Firefox Safe Mode?

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Just now I tried to quit. It took about 30 seconds for the windows to close, but Activity Monitor showed it was still running -- alternating between a relatively high %CPU usage (80%) and low (10%) and becoming NOT RESPONDING from time to time , for about another 30 seconds. Then my Mac crashed with the Grey Curtain of Death.

I'm thinking that Firefox fails at memory management when I have a lot of tabs & windows open. It needs to do a better job of warning me when its reaching its limitations on open stuff. Better yet, stop refreshing background calls to tabs I have not used in a while.

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Do you have (third-party) security software running on your Mac?

If that is the case then try to disable this software to see if that has effect.

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No security software. And DSLReports speed test says I'm meeting the tariff speeds for up & downloads.