I think the problem is more in the MBSDK Soap request than in the LANDESK limitation. In the request certain characters may be read like escape characters.
I just created a Task directly in LANDESK called _-+=)(*& ^%$# @!~?/>.<,
I don't think it's a good idea, but it works
As Frank suggested, In general, stick to a-z, A-Z, 1-0 ... that's about it. Avoid most special characters as they can (/would) cause trouble in the DB-side and are a pain to deal with.
Makes life easiest.
Use of "-" and "_" is also fine ... should keep you going through most things.