why is this month different than all other months? A chiddush of the Ba"ch

The gemara on the last daf of R"H has the following din:

 אמר ר"א לעולם יסדיר אדם תפלתו ואח"כ יתפלל

 

You have to prepare your davening in advance.  (The poskim write that if someone davens from a siddur, that is sufficient.  If you daven by heart, you have to look over the tefilah.)

 

The gemara then qualifies that statement:

 

מר רבי אבא מסתברא מילתיה דר' אלעזר בברכות של ר"ה ושל יוה"כ ושל פרקים אבל דכל השנה לא איניוהא רב יהודה מסדר צלותיה ומצלי שאני רב יהודה כיון דמתלתין יומין לתלתין יומין הוה מצלי כפרקים דמי 

It seems like 30 days is the threshold for what constitutes an interval of פרקים.  Does that mean day 30 is already outside the limit, or does that mean going *beyond* 30 days is the limit?  The nafka mina would be tefilah on Rosh Chodesh.  Tur in Siman 100:

 

וצריך להסדיר תפלתו קודם שיתפלל כדי שתהא שגורה בפיו  ודוקא תפלה של פרקים לפי שאינו רגיל בה אבל תפלות התדירות לא וכתב הרמב"ם ז"ל של פרקים כגון של ר"ח ומועדות וא"א ז"ל כתב של פרקים הוא משלשים יום ואילך ולפ"ז ר"ח א"צ

 

For some reason it just dawned on me this year that Rosh Chodesh Cheshvan should be an exception to the above machlokes.  While it is possible for Rosh Chodesh of other months to fall within the 30 day limit, it's impossible when it comes to Cheshvan.  Our tefilah on R'Ch Tishrei is not a Rosh Chodesh tefilah -- it's the tefilah of R"H.  Therefore, when Cheshvan rolls around, it's actually been 2 months since the last R"Ch davening.  I found the point in the Ba"Ch:

 

מיהו אף לפי זה של ראש חדש מרחשון צריך הוא להסדיר שהרי לא התפלל לתפלת ראש חדש בראש השנה ואיכא ח' שבועות מראש חדש אלול עד ראש חדש חשון שלא התפלל תפלת ראש חדש

So there you have it -- something unique to this Rosh Chodesh.