PP login page in english -- works
day limit depends on number of purchases -- works
(btw: secure hole: do 10 purchases for 0.01, get max  limit - buy all - withdraw money. Maybe, limit should be % of  all prev purchases, like 120%).

dynamic price - no ( )
mtgox: 6.55
donotcompare: 10

>>5 hours??! Wow, thanks for your patience, really    When I receive the payment notification I often check if the
>> balance has decreased, and it has. Sometimes it takes a while for the receiver to see its balance increased (it
>> happens to me when I move money between wallets). But still, 5 hours... it must have been an exceptional case.

well, i just checked my transfers from deepbit -- 1h 30min average between DeepBit Payment tab time and my client time.

in dontcompare's case PP payment were at 25.08.2011 23:35:37 UTC+3
and client lists transaction as Date: 8/26/11 06:57 UTC+3
block explorer lists that transaction as: 2011-08-26 03:57:36 UTC

even sending from one wallet to another isn't instant, IIRC ( don't want to restart client now to check )

I think sender see immediate balance decrease, but not receiver.
(Hint, maybe, it worth to write on exchange page about this delay )

1. i suggest you disable Sent Pin button after it pressed. I almost pressed it again since there is no HUGE CENTER SCREEN RED message "pin sent" ..

2. the first PP screen (one that asks for login / password) not in english (spanish?). It may scary some people who might think it is fishing site. After login it is on my local language.

3. This time btc's arrived in my client just after i pressed Pay in PP. Previous time it took 5 hours between your confirmation and actual arrive (actualy, may be i just got REALLY lucky this time )

4. Just to confirm: all next excahnges should be done with the PIN i just got ? no need to press Get PIn again for me ?(As long as i use seme phone number sure).

why you identify by phone ?
isn't receive address unique enough for it ?

Also, you can hash not phone itself but some constant text + phone
thus leaking only db won't harm anyone

yep, -rescan seems exactly the thing you're looking for:
 -rescan            Rescan the block chain for missing wallet transactions