Three of four times a week Skype won't open.

I have to uninstall it then reinstall. It'd no big deal, takes a few minutes.

It only happens since I upgraded to 5.0. I got rid of it and went back to 4.2 etc but the problem has remained.

Hmmmm...I have 5.1.0.104. Use it about 2 times a week and have not had any problems. What OS are you running?

Edit: here is an interesting thread:

http://social.answers.microsoft.com/Forums/en-US/w7programs/thread/81e525b9-fda6-46b9-9793-eb09c52ddd3a

Still running XP, buying a new desk top set up next week, will probably install Windows7 then.

The general absence of bugs and clutter lurking in the current system will almost certainly work wonders anyway.

Have you tried the Skype help online? A lot of bloggers there that are usually very helpful.

http://mac.oldapps.com/

I had all that yesterday. I deleted the 5 and went back to 2 courtesy of the site above. Excellent. There is a non mac page too.

Could it be you merely closed the Skype window; you already are signed in; you have Skype hidden in the notifications area; and you have the option (in the advanced settings) to keep Skype in the taskbar when you are signed in, unchecked?