hf3d error using eigenmode solution when searching for higher modes in a cavity

I've been trying to simulate a microwave cavity and find higher order resonances, particularly the TE141, which, for my geometry should be up near 27GHz. The solution setup works fine for lower frequency resonances (like the TE111 near 4.5GHz) but begins to give me the following error as I raise the minimum frequency.

[error] Adaptive solution setup, process hf3d error: No eigenmodes were found. This could be caused by a very lossy or very open structure, or the spectrum of modes may be nearly continuous.. (4:51:24 PM Jun 17, 2013)

How can I fix this?

The cavity does support many more modes as I raise the frequency, and I have been able to get around this error by raising the maximum number of passes. But now I have the number of passes maxed out at 99 and am still getting the error!

I have:
Minimum Starting Frequency: 27GHz
Maximum number passes: 99
Maximum Delta Frequency per Pass: 1%

I've also uploaded my hfss files and some .SAT drawings which I used to import the geometry from solidworks. There are two versions one longer and symetrical in the z-coordiate (cylindrical coordinates) and another shorter one where I tried to use a symmetry plane to reduce the amount of computation hfss has to do (using this symmetry helped a bit with this error, in roughly the 20 - 25GHz range, but not much higher)

Any help is MUCH APPRECIATED!BulgeCavity.zip