Version 2.1 of the maxfilter software has been released in the end of 2009. If you are at the CBU you can access the manual on the ElektaSoftwareManuals page. Maxfilter 2.1 will soon be available, initially alongside version 2.0. For the moment the recommendation is to use version 2.0.
Currently known bugs
Spatio-temporal extension in MF2.1 crippled. A number of files cannot be processed with the ST version of SSS, which happens when it can't fit integer number of buffer lengths to the total file length.
Maximum file size bug - movecomp. Files of the maximum allowed size (2G) cannot be movecomped. Apparently, the new MF 2.1 adds extra channels as a result of movement correction which increases the size even further causing MF to abort. This cannot be overriden by any other options including downsampling. This is a bug, and ENM were informed. Recording files of <1.8G is recommended to avoid this.
Head origin default. Unless head origin coordinates are specified explicitely, default values of 0, 0, 40 are applied.
Suppression of brain signals in MF2.1. Spatiotemporal signal space separation (tSSS) may, under certain rare conditions, suppress signals emanating from the brain. Under such conditions, the signal space separation is unable to perfectly separate signals arising from the internal, external, and artifact signal spaces, resulting in leakage of brain signals into the artifact signal space and in their subsequent suppression. For the above to happen, the reconstruction error of the brain signal must be large enough to cause leak into the artifact signal space with amplitude exceeding the noise level. Under certain circumstances, this may be the case even though only a very small percentage of the brain signal leaks into the artifact signal space.
Abortions. Because of changes in noise estimatation/reduction algorythm, a small number of files that could be processed in MF 2.0. cause MF 2.1 to abort.