Full Text message: Work area overflown due to many hits

I was facing with strange error.

11.11.2008 00:37:34   Full Text message: Work area overflown due to many hits. Error-Number = 130

11.11.2008 00:37:34   GTR search error for "D:\Lotus\Domino\Data\Referent\DD\ddagr.ft\UNDX\ftgi0000": Work area overflown due to many hits. Error-Number = 130: Full text error; see log for more information

The error happened each time at line with NotesDatabase.FTSearch(query, 0)

query = (([Form]="AgrAddon") & ( ([AgrDate]=08.07.2005 & [AgrAddonDate]=25.06.2008 & !([AgrAddonNum]=("-" | "/")) )))

What I found in the internet (especially at IBM forum) that this problem could be because of this part of query [AgrAddonNum]=("-" | "/").

Actually sometimes(?) symbols - , ; : \ return this error. So I changed query and it worked well (I hope it will not repeat anymore)