IIS7: Content-Length Mismatch Due to URL Rewrite and OutboundRules Usage - caching

Question

I'm having some issues getting the outbound rules configured to work on IIS7, here's the scenario that's giving me grief. My ultimate goal is to get any outboundRules working within a couple of browsers. For this example, I'm using the rule that strips .aspx from various HTML tags.
Scenario 1 (Content-Length Mismatch):
To get that particular rule to work in IIS7, I had to disable dynamic compression and turn caching off by default. I was successful in getting the HTML rewritten, but another issue cropped up that makes this unusable.
When trying the rewrite content with outboundrules, I'm getting an issue where by Chrome and Firefox are performing a continuous load because of a "content-length mismatch" in the headers (Thanks Fiddler for helping me identify it). The rewrite works, but it causes the content length to be incorrect and so those two browsers look like they're loading forever. Chrome in particular this causes an issue because javascript appears to be hung up and so anything jquery doesn't work until someone physically hits the stop button.
This is the pertinent sections of the web.config that I began with in order to give me that scenario:
<system.webServer>
<rewrite>
<urlCompression doStaticCompression="false" doDynamicCompression="false" dynamicCompressionBeforeCache="false" />
<modules runAllManagedModulesForAllRequests="true" />
<outboundRules>
<rule name="Remove .aspx from links in the response" preCondition="IsHTML" stopProcessing="false">
<match filterByTags="A, Area, Base, Form, Frame, IFrame, Link, Img, Script" pattern="(.*)\.aspx(\?.*)?$" />
<action type="Rewrite" value="{R:1}{R:2}" />
</rule>
<preConditions>
<preCondition name="IsHTML">
<add input="{RESPONSE_CONTENT_TYPE}" pattern="^text/html" />
</preCondition>
</preConditions>
</outboundRules>
</rewrite>
<caching enabled="false" enableKernelCache="false" />
</system.webServer>
While researching this issue, I found this stackedoverflow question which mentioned the rewriteBeforeCache="true" attribute on the outboundRules tag as well as this blog post which laid out the same thing that I was running into with the content-length issues.
If I modify that attribute, that leads me to Outbound Rules failing to work any further.
Scenario 2 (Outbound Rules do not work):
So because of the prior information, I began tweaking the web.config and was able to resolve the content-length mismatch by using the rewriteBeforeCache attribute on the outboundRules tag. To get that attribute to work, I was able to turn caching back on. That fixed the reponse-length mismatch from Scenario 1, but now none of the outboundRules\rule elements appear to work. I have tried a number of the simplest rules and they function just fine when I remove the rewriteBeforeCache attribute, but that causes Scenario 1:
<system.webServer>
<rewrite>
<urlCompression doStaticCompression="false" doDynamicCompression="true" dynamicCompressionBeforeCache="false" />
<modules runAllManagedModulesForAllRequests="true" />
<outboundRules rewriteBeforeCache="true">
<rule name="Remove .aspx from links in the response" preCondition="IsHTML" stopProcessing="false">
<match filterByTags="A, Area, Base, Form, Frame, IFrame, Link, Img, Script" pattern="(.*)\.aspx(\?.*)?$" />
<action type="Rewrite" value="{R:1}{R:2}" />
</rule>
<preConditions>
<preCondition name="IsHTML">
<add input="{RESPONSE_CONTENT_TYPE}" pattern="^text/html" />
</preCondition>
</preConditions>
</outboundRules>
</rewrite>
</system.webServer>
Scenario 1 causes one error with browsers in IIS7; Scenario 2 causes outboundrules to stop working.
I have modified any number of options with disabling caching, chunk-mode transfers, and trying every combination I can think to try.
Additional notes on AppPool: IIS7, .NET4.0, Classic pipeline
Does anyone else have any ideas as to what other options I have to address this beyond moving to an IIS7.5 server?