I am following excession's article on observing hands before deciding to sit down.
So... I login to PP, click open 4 tables of 50NL...open up PT and let it start observing hands...I leave for a bit (10 -15 mins). I come back, click on the join waitlist for the specific table(s) I am obseving and eventually the window pops up saying there is a seating waiting for me at one of those tables that I am watching.

Here is the problem: I immediately click take the seat, my cashier thing pops up and I click the buy in with $50, click ok and it tells me something like: You did not sit down in time. So I cant sit and get back on the waitlist and the same thing happens over and over.

I finally give up and sit first, have them deal me out for about 10mins while PT observes and then I start a hand...

Can someone tell me how to correct this?

It's been awhile since you asked this but I was having this problem recently as well. I contacted PP about it and they instructed me to uninstall their software totally and then redownload it and reinstall. They also said to make sure I cleared my temp files and cookies before going to their site to download the software.
Well, I did as they instructed and all seems to be well now for the most part. Only had it do it one time in the last 3 days now whereas it was doing it every single time I tried to get on a table.
Worked for me, try it if you want to.