I saw Andrej‘s post on the new Infragistics Netadvantage Vol. 3 for CLR 2.0 (VS2005/.net 2.0 that is) and went investigating what’s up. As you remember weird things are going on with VS 2005’s visual inheritance support. Fortunately, Developer Express managed to workaround these new VI barriers imposed by Microsoft. The same can’t be said for Infragistics though. After the brief investigation I found that NetAdvantage’s UltraGrid (haven’t tested other complex controls) has big issues with VI and you should be very careful when using it in VI scenarios. It doesn’t lockdown entirely as MS’ DataGridView does (collection properties are locked down as usual) it just doesn’t implement VI properly (note that I don’t have any experience with previous NetAdvantage versions).
For example, I put an UltraGrid on the form, set its modifier to protected, add a column and inherit such form. Now, the column appears properly on the derived form but just as long as you don’t change anything on the base form. The reason is simple: UltraGrid rewrites columns on the derived form instead of inheriting them – that is completely useless behavior for VI. On the bright side I can say that UltraGrid isn’t just disabled on derived forms.