Since you're running the latest build of TCPMP, it's not surprising those old aac CABs fail. REV27 should already have AAC support. I'm running a little older TCPMP on my Vogue, TCPMP-0.72RC2-ARM-WM6, and it's working too well for my needs to bother messing with it. But wait, AAC stands for advanced
audio codec, right? Are you sure you have:
>...an AAC encoded movie...
Maybe it's actually an MOV file with the audio track encoded AAC? If so, try changing the extension. Another issue that may apply is that the skinnable RC2 version is very picky about needing to have NO old TCPMP files or registry keys from past versions. Had so much trouble finding and dumping them all, that I ended up doing a hard reset. If you have MortScript, there's a CAB at xda-developers to clean out old TCPMP:
[UPDATE 2010-09-18] Yet another TCPMP build [SKINNED+AVRCP] - Page 61 - xda-developers