Rated 4 out of 5 stars

Great product. Works in FF, but not working in SM2.1b1 (Seamonkey 2.1Beta 1).

This review is for a previous version of the add-on (1.5.3). 

Thanks for your report. I will be testing before I release the next version. Note the declared compatibility: 2.0 - 2.1a3. SM 2.1b1 is not included in that range, so of course SM will refuse to allow it to be installed. Make sure you understand the difference between the declared compatibility and actual compatibility, which might well include 2.1b1; I just haven't tested it yet.

A possibility is to installed Add-on Compatibility Reporter. This will override the compatibility control and let you try out add-ons not declared compatible; you can make compatibility reports to Mozilla. I have no reason to believe SPE will not work with 2.1b1, but be warned that some truly non-working add-ons may cause you problems.

Finally, if you want to get support or make bug reports to me, please use the support link near the upper-right on the details page; reviews are not suitable for support as I have no way to contact you.