IIS Hanging issue

I made a test below on IIS 7.5:

1.   Only 2 webpage:

     Page A has a dead 'while sentence':
<% i = 0
while i<1
i = 0 
wend
%> 

    Page B only print 'Hello'.

2.   Now I start IIS.

      2a.   If you visit  page-A first... then visit page-B... Page-A will dead of course (time out after sometime), but Page-B shows well.
      2b.   now restart IIS.   Then, If you visit  page-B first, then visit Page-A, then again visit page-B...  the 'Page-B' also dead (until page-A timeout)

I tried to add more 'work process',  or increase 'MaxPoolThreads' in regedit,..  the result is the same...

I couldnt find any solution from internet about the same... I don't know if I have any wrong understanding, or it appears to be a bug... Please kindly advise me...