Hi,
I also have the same freezing issue opening Philips SDAT spectra using JMRUI v5.2 with Windows 7 and 32-bit Java. We also use the trick to ask a colleague to open it on another computer or try with an older JMRUI version, which sometimes works.
In some cases, using the “File/Open as…” menu is more successful. Another option is to open the problematic spectrum together with another similar one, not affected by this bug.
It is hard to give a good example to work on, as this seems to happen randomly on different computers. However, when one spectrum shows this freezing problem on a given computer, it will always freeze.
Best,
Bernard