Size of showthread.php and forumdisplay, etc.

[pjkcards]

Hello,
Late last month, I decided to move my forum from domain.com to domain.com/forum, and install vBa CMPS on the homepage. I also removed my second navbar and added some drop-down menu's to the first navbar instead (do drop-downs increase page size a lot?).

The next day, my bandwidth for this particular site jumped up from around 500-700MB per day to over 1.6GB. I assumed it was the CMPS I installed. The other day I setup a redirect so that all traffic to the site would be directed to the forum, basically turning off the CMPS. The bandwidth basically did not change, telling me it wasn't the CMPS.

I contacted my host, and they are next to no help with this. I checked the logs and didn't see anything out of ordinary.

I checked Awstats and I think I have found the problem, but do not know why it exists and/or how to correct it, and I am asking for your help.
I checked and I saw this in the stats:
php Dynamic PHP Script file 343248 16.3 % 13.44 GB 71.8 %
That seems to be accounting for most of the bandwidth (71.8% of the site). So I know it is a php file most likely sucking up the bandwidth. So I went on to see what files were using the most.
For forum/showthread.php, average size is 70.72KB, forum/forumdisplay.php is 72.51KB, while index.php is 52.91KB. The month before, these file sizes were around 15-20KB at most, with index.php only at 15KB. What can cause the forum/forumdisplay, index and forum/showthread to increase so much? In the stats it has these two interesting stats:
/forum/forumdisplay.php 10081 72.31 KB (Avg Size)
/forumdisplay.php 64478 19.74 KB (Avg Size)

Forumdisplay and showthread were increased the most, but pretty much all files increased, such as:
newreply.php 12.05KB (Avg Size)
forum/newreply.php 27.65KB (Avg Size)

These are the stats from last month, comparing the size of the same file, one in the domain.com directory, and then the file after I moved it.

That means putting it into the forum sub-directory caused the increase, or something similar I did when I moved the forum to /forum. The only things I did was move the forum and change the navbars. Any ideas on correcting this problem? The only major thing I did was move the forum to a sub-directory, and install CMPS (which I think I have ruled out as the problem).

Thanks in advance, I greatly appreciate the assistance.